diff --git a/src/common-principles.md b/src/common-principles.md
index 0a42e4a885..179333f6cb 100644
--- a/src/common-principles.md
+++ b/src/common-principles.md
@@ -85,7 +85,7 @@ saved under a particular filename specified in the standard. This standard
 aspires to describe a majority of datasets, but acknowledges that there will be
 cases that do not fit. In such cases one can include additional files and
 subdirectories to the existing directory structure following common sense. For example
-one may want to include eye tracking data in a vendor specific format that is
+one may want to include eye-tracking data in a vendor specific format that is
 not covered by this standard. The most sensible place to put it is next to the
 continuous recording file with the same naming scheme but different extensions.
 The solutions will change from case to case and publicly available datasets will
diff --git a/src/modality-specific-files/physiological-recordings.md b/src/modality-specific-files/physiological-recordings.md
index 8db4a03a02..cb125e215a 100644
--- a/src/modality-specific-files/physiological-recordings.md
+++ b/src/modality-specific-files/physiological-recordings.md
@@ -1,10 +1,5 @@
 # Physiological recordings
 
-Physiological recordings such as cardiac and respiratory signals MAY be
-specified using a [compressed tabular file](../common-principles.md#compressed-tabular-files)
-([TSV.GZ file](../glossary.md#tsv_gz-extensions)) and a corresponding
-JSON file for storing metadata fields (see below).
-
 !!! example "Example datasets"
 
       [Example datasets](https://bids-standard.github.io/bids-examples/#dataset-index)
@@ -14,41 +9,167 @@ JSON file for storing metadata fields (see below).
       -   [`7t_trt`](https://github.com/bids-standard/bids-examples/tree/master/7t_trt)
       -   [`ds210`](https://github.com/bids-standard/bids-examples/tree/master/ds210)
 
-Template:
+## General specifications
 
-```Text
-sub-<label>/[ses-<label>/]
-    <datatype>/
-        <matches>[_recording-<label>]_physio.tsv.gz
-        <matches>[_recording-<label>]_physio.json
-```
+Continuous (that is, regularly sampled over time at a fixed frequency)
+physiological recordings such as cardiac and respiratory signals, and
+asynchronous events corresponding to those signals MAY be specified using
+[compressed tabular files](../common-principles.md#compressed-tabular-files)
+([TSV.GZ file](../glossary.md#tsvgz-extensions)).
+TSV.GZ files MUST be accompanied by a JSON file with the same name as their
+corresponding tabular file but with a `.json` extension.
 
-For the template directory name, `<datatype>` can correspond to any data
-recording modality, for example `func`, `anat`, `dwi`, `meg`, `eeg`, `ieeg`,
-or `beh`.
+!!! warning "Caution"
 
-In the template filenames, the `<matches>` part corresponds to task filename
-before the suffix.
-For example for the file `sub-control01_task-nback_run-1_bold.nii.gz`,
-`<matches>` would correspond to `sub-control01_task-nback_run-1`.
+    Columns of TSV.GZ files MUST be defined in the corresponding JSON sidecar
+    and the tabular content MUST NOT include a header line.
+
+Summary template:
+
+<div class="highlight">
+<pre><code><a href="../appendices/entities.html#sub">sub-&lt;label&gt;</a>/
+    [<a href="../appendices/entities.html#ses">ses-&lt;label&gt;</a>/]
+        &lt;<a href="../glossary.html#data_type-common_principles">datatype</a>&gt;/
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_&lt;<a href="../glossary.html#physio-suffixes">physio</a>|<a href="../glossary.html#physioevents-suffixes">physioevents</a>&gt;<a href="../glossary.html#json-extensions">.json</a>
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_&lt;<a href="../glossary.html#physio-suffixes">physio</a>|<a href="../glossary.html#physioevents-suffixes">physioevents</a>&gt;<a href="../glossary.html#tsvgz-extensions">.tsv.gz</a>
+</code></pre></div>
+
+For the template directory name, `<datatype>` can correspond the following
+[data types](../glossary.md#data_type-common_principles):
+`beh`, `dwi`, `eeg`, `func`, `ieeg`, `meg`, `motion`, `nirs`, `perf`, or `pet`.
+In the template filenames, the `<matches>` part corresponds to those entities
+before the suffix that identify the reference run.
+For example, for the file `sub-01_task-nback_run-1_bold.nii.gz`,
+`<matches>` would correspond to `sub-01_task-nback_run-1`.
+Note that when supplying a `<matches>_<physio|physioevents>.tsv.gz` file,
+an accompanying `<matches>_<physio|physioevents>.json` MUST be supplied as well.
+
+<details class="tip">
+<summary>Expanded filename template</summary>
+<!--
+This block generates a filename templates.
+The inputs for this macro can be found in the directory
+  src/schema/rules/files/raw
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filename_template(
+       "raw",
+       datatypes=["beh", "dwi", "eeg", "func", "ieeg", "meg", "motion", "nirs", "perf", "pet"],
+       suffixes=["physio", "physioevents"],
+       title="The above summary template is expanded for the acceptable data types as follows:",
+   )
+}}
+</details>
+
+For multi-echo data, a single `_<physio>.<tsv.gz|json>` file without the
+[`echo-<index>`](../appendices/entities.md#echo) entity applies to all echos of
+a particular run.
+For example:
 
-!!! warning "Caution"
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-nback_run-1_echo-1_bold.nii.gz": "",
+      "sub-01_task-nback_run-1_echo-2_bold.nii.gz": "",
+      "sub-01_task-nback_run-1_echo-3_bold.nii.gz": "",
+      "sub-01_task-nback_run-1_physio.tsv.gz": "",
+    },
+  },
+}) }}
+
+This specification section first describes the organization of
+[continuous physiological recordings](#continuous-physiological-recordings), and
+then [events corresponding to the physiological recordings](#physiology-events).
+Finally, the remainder of the document describes
+[specific types of continuous recordings](#specific-physiological-signal-types)
+such as [eye-tracking](#eye-tracking).
+
+## Continuous physiological recordings
+
+Continuous physiological recordings, such as pulse monitoring,
+electrocardiogram, respiratory movement measured with a respiration belt,
+gas concentration, eye-tracking, or head-motion parameters estimated
+by the MRI scanner, MUST use `_physio.<tsv.gz|json>` pairs.
 
-    `<matches>_physio.tsv.gz` files MUST NOT include a header line, as established by the
-    [common-principles](../common-principles.md#compressed-tabular-files).
-    As a result, when supplying a `<matches>_physio.tsv.gz` file, an accompanying
-    `<matches>_physio.json` MUST be present to indicate the column names.
+Template:
+
+<div class="highlight">
+<pre><code><a href="../appendices/entities.html#sub">sub-&lt;label&gt;</a>/
+    [<a href="../appendices/entities.html#ses">ses-&lt;label&gt;</a>/]
+        &lt;<a href="../glossary.html#data_type-common_principles">datatype</a>&gt;/
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_<a href="../glossary.html#physio-suffixes">physio</a><a href="../glossary.html#json-extensions">.json</a>
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_<a href="../glossary.html#physio-suffixes">physio</a><a href="../glossary.html#tsvgz-extensions">.tsv.gz</a>
+</code></pre></div>
 
+**Storing different recordings**.
 The [`recording-<label>`](../appendices/entities.md#recording)
 entity MAY be used to distinguish between several recording files.
-For example `sub-01_task-bart_recording-eyetracking_physio.tsv.gz` to contain
-the eyetracking data in a certain sampling frequency, and
-`sub-01_task-bart_recording-breathing_physio.tsv.gz` to contain respiratory
-measurements in a different sampling frequency.
+Recordings with different metadata such as sampling frequencies
+or recording device MUST be stored in separate files with different
+[`recording-<label>`](../appendices/entities.md#recording) entities.
+For example, given a multi-echo acquisition corresponding to a breath-holding
+task (`task-bht`) for which pulse and respiratory movement were
+sampled at different frequencies, recordings are separated as follows:
 
-Physiological recordings (including eyetracking) MUST use the `_physio` suffix.
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-bht_echo-1_bold.nii.gz": "",
+      "sub-01_task-bht_echo-2_bold.nii.gz": "",
+      "sub-01_task-bht_echo-3_bold.nii.gz": "",
+      "sub-01_task-bht_recording-cardiac_physio.json": "",
+      "sub-01_task-bht_recording-cardiac_physio.tsv.gz": "",
+      "sub-01_task-bht_recording-respiratory_physio.json": "",
+      "sub-01_task-bht_recording-respiratory_physio.tsv.gz": "",
+    },
+  },
+}) }}
+
+**Metadata fields for `<matches>_<physio>.json` files**.
+General metadata fields include `SamplingFrequency`, `StartTime`, `Columns`,
+and `Manufacturer`, in addition to individual column descriptions.
+Each individual column in the TSV file MAY be documented as its own field in the JSON file
+(identical to the practice in other TSV+JSON file pairs).
 
-The following tables specify metadata fields for the `*_physio.json` file.
+!!! warning "Caution"
+
+    Recordings with different key metadata MUST be split into separate files.
+
+When key metadata such as sampling frequencies, manufacturers varies between recordings,
+tabular data MUST be split into separate files.
+In such cases, the [`recording-<label>`](../appendices/entities.md#recording)
+entity MUST be used to distinguish these files.
+
+Metadata sidecar files (`<matches>_physio.json`) MAY define the field
+`PhysioType` to indicate a specific type of recording.
+The default value of `PhysioType` is `"generic"`, and MUST be assumed
+if the `PhysioType` metadata is not defined.
+Specific recording types (that is, when `PhysioType` takes a valid value other than `"generic"`)
+have separate prescriptions for columns in the TSV.GZ files and corresponding metadata
+specifications.
+
+!!! tip "RECOMMENDED"
+
+    Using specific recording types is RECOMMENDED when available in the
+    specification.
+
+    The allowed physiological recording types encoded by `PhysioType` and
+    their corresponding metadata specifications are described in subsection
+    [Specific physiological signal types](#specific-physiological-signal-types)
+    below, and its subsections:
+
+    -   eye-tracking ([subsection Eye-tracking](#eye-tracking)).
+
+The following table specifies metadata fields for `"generic"` recordings:
 
 <!-- This block generates a metadata table.
 These tables are defined in
@@ -58,9 +179,10 @@ The definitions of the fields specified in these tables may be found in
 A guide for using macros can be found at
  https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
 -->
-{{ MACROS___make_sidecar_table(["continuous.Continuous"]) }}
+{{ MACROS___make_sidecar_table(["continuous.Continuous", "continuous.PhysioTypeRecommended"]) }}
 
-## Hardware information
+**Hardware information**.
+Details about the hardware MAY be stored with the following metadata fields.
 
 <!-- This block generates a metadata table.
 These tables are defined in
@@ -72,27 +194,35 @@ A guide for using macros can be found at
 -->
 {{ MACROS___make_sidecar_table(["continuous.PhysioHardware"]) }}
 
-Additional metadata may be included as in
-[any TSV file](../common-principles.md#tabular-files) to specify, for
-example, the units of the recorded time series.
-
-Example `*_physio.tsv.gz`:
+**Column naming recommendations for `"generic"` recordings.**
+To store pulse or breathing measurements, or the scanner trigger signal,
+the following naming conventions MAY be used for the column names:
+<!-- This block generates a columns table.
+The definitions of these fields can be found in
+  src/schema/rules/tabular_data/*.yaml
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_columns_table("physio.PhysioColumns") }}
 
+**Examples**.
+Let's encode cardiac and respiratory recordings, as well as a trigger signal,
+the three of them sampled at 100.0 Hz by the same device during a behavioral task:
 <!-- This block generates a file tree.
 A guide for using macros can be found at
  https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
 -->
-{{ MACROS___make_filetree_example(
-   {
-   "sub-control01": {
-      "func": {
-         "sub-control01_task-nback_physio.tsv.gz": "",
-         },
-      },
-   }
-) }}
-
-(after decompression)
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-nback_physio.json": "",
+      "sub-01_task-nback_physio.tsv.gz": "",
+    },
+  },
+}) }}
+
+In this example, the contents of `sub-01_task-nback_physio.tsv.gz`
+after decompression are:
 
 ```Text
 34    110    0
@@ -100,94 +230,567 @@ A guide for using macros can be found at
 23    100    1
 ```
 
-Example `*_physio.json`:
-
-<!-- This block generates a file tree.
-A guide for using macros can be found at
- https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
--->
-{{ MACROS___make_filetree_example(
-   {
-   "sub-control01": {
-      "func": {
-         "sub-control01_task-nback_physio.json": "",
-         },
-      },
-   }
-) }}
+and the header-less TSV.GZ contents are described with the following
+metadata `sub-01_task-nback_physio.json` where the `Columns` field defines
+the names corresponding to the three columns above:
 
 ```JSON
 {
+    "Columns": ["cardiac", "respiratory", "trigger"],
+    "Manufacturer": "Brain Research Equipment ltd.",
+    "PhysioType": "generic",
     "SamplingFrequency": 100.0,
     "StartTime": -22.345,
+    "cardiac": {
+      "Description": "continuous pulse measurement",
+      "Units": "mV"
+    },
+    "respiratory": {
+      "Description": "continuous measurements by respiration belt",
+      "Units": "mV"
+    },
+    "trigger": {
+      "Description": "continuous measurement of the scanner trigger signal",
+      "Units": "V"
+    }
+}
+```
+
+The example shows the three REQUIRED metadata entries `Columns`, `SamplingFrequency`,
+and `StartTime`.
+Columns are further described following the specifications for
+[tabular files](../common-principles.md#tabular-files),
+indicating `Description` and `Units` fields.
+Other fields, such as `TermURL`, `LongName`, MAY be included.
+
+The `PhysioType` can be omitted as the recordings are `"generic"`:
+
+```JSON
+{
     "Columns": ["cardiac", "respiratory", "trigger"],
     "Manufacturer": "Brain Research Equipment ltd.",
+    "SamplingFrequency": 100.0,
+    "StartTime": -22.345,
     "cardiac": {
-        "Description": "continuous pulse measurement",
-        "Units": "mV"
-        },
+      "Description": "continuous pulse measurement",
+      "Units": "mV"
+    },
     "respiratory": {
-        "Description": "continuous measurements by respiration belt",
-        "Units": "mV"
-        },
+      "Description": "continuous measurements by respiration belt",
+      "Units": "mV"
+    },
     "trigger": {
-        "Description": "continuous measurement of the scanner trigger signal"
-        }
+      "Description": "continuous measurement of the scanner trigger signal",
+      "Units": "V"
+    }
 }
 ```
 
-Note how apart from the general metadata fields like `SamplingFrequency`, `StartTime`, `Columns`,
-and `Manufacturer`,
-each individual column in the TSV file may be documented as its own field in the JSON file
-(identical to the practice in other TSV+JSON file pairs).
-Here, only the `Description` and `Units` fields are shown, but you may use any other of the
-[defined fields](../common-principles.md#tabular-files) such as `TermURL`, `LongName`, and so on.
-In this example, the `"cardiac"` and `"respiratory"` time series are produced by devices from
-the same manufacturer and follow the same sampling frequency.
-To specify different sampling frequencies or manufacturers, the time series would have to be split
-into separate files like `*_recording-cardiac_physio.<tsv.gz|json>` and `*_recording-respiratory_physio.<tsv.gz|json>`.
+If the `"cardiac"` and `"respiratory"` signals above were acquired at different
+sampling frequencies, then the recordings MUST be separated into two files
+disambiguated by the [`recording-<label>`](../appendices/entities.md#recording)
+entity:
 
-## Recommendations for specific use cases
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-nback_recording-cardiac_physio.json": "",
+      "sub-01_task-nback_recording-cardiac_physio.tsv.gz": "",
+      "sub-01_task-nback_recording-respiratory_physio.json": "",
+      "sub-01_task-nback_recording-respiratory_physio.tsv.gz": "",
+    },
+  },
+}) }}
+
+## Physiology "events"
+
+Discontinuous data associated with continuous recordings
+stored in `<matches>_physio.tsv.gz` files MAY be specified
+following the summary template pattern above.
 
-To store pulse or breathing measurements, or the scanner trigger signal, the
-following naming conventions SHOULD be used for the column names:
+Template:
 
-<!-- This block generates a columns table.
+<div class="highlight">
+<pre><code><a href="../appendices/entities.html#sub">sub-&lt;label&gt;</a>/
+    [<a href="../appendices/entities.html#ses">ses-&lt;label&gt;</a>/]
+        &lt;<a href="../glossary.html#data_type-common_principles">datatype</a>&gt;/
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_<a href="../glossary.html#physioevents-suffixes">physioevents</a><a href="../glossary.html#json-extensions">.json</a>
+            &lt;matches&gt;[_<a href="../appendices/entities.html#recording">recording</a>-&lt;<a href="../glossary.html#label-common_principles">label</a>&gt;]_<a href="../glossary.html#physioevents-suffixes">physioevents</a><a href="../glossary.html#tsvgz-extensions">.tsv.gz</a>
+</code></pre></div>
+
+Placeholders such as `<datatype>` and `<matches>` are defined
+as above for the template of continuous recordings.
+The [`recording-<label>`](../appendices/entities.md#recording)
+entity is OPTIONAL, but MUST be matched with an existing
+`<matches>[_recording-<label>]_physio.tsv.gz` file.
+
+Physiology "events" files `<matches>_recording-<label>_physioevents.tsv.gz`
+MUST follow specific column specifications:
+
+<!--
+This block generates a columns table.
 The definitions of these fields can be found in
-  src/schema/rules/tabular_data/*.yaml
+  src/schema/rules/tabular_data/eyetrack.yaml
 and a guide for using macros can be found at
  https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
 -->
-{{ MACROS___make_columns_table("physio.PhysioColumns") }}
+{{ MACROS___make_columns_table("physio.PhysioEventsColumns") }}
 
-For any other data to be specified in columns, the column names can be chosen
-as deemed appropriate by the researcher.
+The following table specifies metadata fields for the
+`<matches>[_recording-<label>]_physioevents.json` file.
 
-Recordings with different sampling frequencies or starting times should be
-stored in separate files
-(and the [`recording-<label>`](../appendices/entities.md#recording)
-entity MAY be used to distinguish these files).
+<!-- This block generates a metadata table.
+These tables are defined in
+  src/schema/rules/sidecars
+The definitions of the fields specified in these tables may be found in
+  src/schema/objects/metadata.yaml
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_sidecar_table(["continuous.PhysioEvents"]) }}
 
-For motion parameters acquired from MRI scanner side motion correction, the
-`_physio` suffix MUST be used.
+The `ForeignIndexColumn` metadata specifies whether
+`<matches>[_recording-<label>]_physio.tsv.gz` files are
+implicitly or explicitly indexed.
 
-For multi-echo data, a given `physio.tsv` file is applicable to all echos of
-a particular run.
-For example:
+**Implicit indexing of `<matches>_physioevents.tsv.gz` files**.
+When `ForeignIndexColumn` is not provided, the `"onset"` column
+corresponds to the one-based row number of the associated
+`<matches>_physio.tsv.gz` file.
+The `"onset"` column accepts negative values to register
+events occurred before the recording(s) in the corresponding
+`<matches>_physio.tsv.gz` file started.
+
+For example, considering the following structure:
 
 <!-- This block generates a file tree.
 A guide for using macros can be found at
  https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
 -->
-{{ MACROS___make_filetree_example(
-   {
-   "sub-01": {
-      "func": {
-        "sub-01_task-cuedSGT_run-1_physio.tsv.gz": "",
-        "sub-01_task-cuedSGT_run-1_echo-1_bold.nii.gz": "",
-        "sub-01_task-cuedSGT_run-1_echo-2_bold.nii.gz": "",
-        "sub-01_task-cuedSGT_run-1_echo-3_bold.nii.gz": "",
-         },
-      },
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-nback_physio.json": "",
+      "sub-01_task-nback_physio.tsv.gz": "",
+      "sub-01_task-nback_physioevents.json": "",
+      "sub-01_task-nback_physioevents.tsv.gz": "",
+    },
+  },
+}) }}
+
+where the decompressed contents of `sub-01_task-nback_physio.tsv.gz`
+are:
+
+```{.text linenums="1"}
+10.1
+10.0
+9.5
+9.2
+9.0
+10.2
+10.3
+10.1
+```
+
+Please note that the above code block has the line numbers enabled,
+but those line numbers are not part of the contents of the file.
+Since there is no explicit column to index the recording,
+the `ForeignIndexColumn` SHOULD NOT be defined in the
+`sub-01_task-nback_physioevents.json` file:
+
+```JSON
+{
+    "Columns": ["onset", "message"],
+    "Description": "Messages logged by the measurement device"
+}
+```
+
+An example of the decompressed contents of the corresponding
+TSV file, `sub-01_task-nback_physioevents.tsv.gz` is:
+
+```TSV
+-3   "Ready"
+3    "Synchronous recalibration triggered"
+6    "External message received: new block"
+```
+
+In this case, the first column lists the indexes (one-based row number)
+from the `sub-01_task-nback_physio.tsv.gz`.
+The first entry, with `"onset"` set to 3, maps to the third line of the
+`sub-01_task-nback_physio.tsv.gz`, indicating that the message
+*Synchronous recalibration triggered* was logged at the same time the
+sample with value `9.5` was registered.
+Likewise, the second message was logged when the recording later registered a
+value of `10.2` (row number 5 of `sub-01_task-nback_physio.tsv.gz`).
+As negative indexes are allowed, the first *Ready* message occurred four sampling
+cycles before the first recorded measurement (line number 1).
+For example, if `SamplingFrequency` in `sub-01_task-nback_physio.json`
+is set to 100 Hz and `StartTime` is -22.345 s, then the *Ready* message was recorded
+0.04 s before the first sample, therefore at -22.305 s.
+
+**Explicit indexing of `<matches>_physioevents.tsv.gz` files (RECOMMENDED)**.
+When the `ForeignIndexColumn` defines a value such as `"timestamp"`,
+that specific column name MUST be present the `<matches>_physio.tsv.gz` file.
+In that case, all values of the `"onset"` column of the
+`<matches>_physioevents.tsv.gz` are indexed by the index established by
+the `ForeignIndexColumn` of the corresponding `<matches>_physio.tsv.gz` file
+(that is, `"timestamp"` in this example).
+It is RECOMMENDED to specify metadata such as `Units` or `Origin`
+corresponding to the column defined by `ForeignIndexColumn`.
+
+For example, let us consider the previous structure:
+
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-nback_physio.json": "",
+      "sub-01_task-nback_physio.tsv.gz": "",
+      "sub-01_task-nback_physioevents.json": "",
+      "sub-01_task-nback_physioevents.tsv.gz": "",
+    },
+  },
+}) }}
+
+However, the `sub-01_task-nback_physio.json` will define now an extra
+column called `"timestamp"`:
+
+```JSON
+{
+    "SamplingFrequency": 100.0,
+    "StartTime": -22.345,
+    "Columns": ["timestamp", "cardiac"],
+    "cardiac": {
+        "Description": "continuous pulse measurement",
+        "Units": "mV"
+    },
+    "timestamp": {
+        "Description": "a continuously increasing identifier of the sampling time registered by the device",
+        "Units": "ms",
+        "Origin": "System startup"
+    }
+}
+```
+
+The decompressed contents of `sub-01_task-nback_physio.tsv.gz`
+are now:
+
+```{.text linenums="1"}
+10.1    13894432329
+10.0    13894432330
+9.5     13894432331
+9.2     13894432332
+9.0     13894432333
+10.2    13894432334
+10.3    13894432335
+10.1    13894432336
+```
+
+Then, the `sub-01_task-nback_physioevents.json` MAY define
+the `ForeignIndexColumn` for indexing:
+
+```JSON
+{
+    "Columns": ["onset", "message"],
+    "Description": "Messages logged by the measurement device",
+    "ForeignIndexColumn": "timestamp"
+}
+```
+
+The decompressed contents of the corresponding TSV file,
+`sub-01_task-nback_physioevents.tsv.gz` could read now:
+
+```TSV
+13894432325    "Ready"
+13894432331    "Synchronous recalibration triggered"
+13894432334    "External message received: new block"
+```
+
+## Specific physiological signal types
+
+### Eye-tracking
+
+<!--
+1. Datasets will be updated later to adapt to the agreed format.
+2. We aim at adding a last example converting published dataset from openeuro.
+-->
+!!! example "Example datasets"
+
+    [Example datasets](https://bids-standard.github.io/bids-examples/#dataset-index)
+    with eye-tracking data have been formatted using this specification
+    and can be used for practical guidance when curating a new dataset:
+
+    -   Combined behavior and eye-tracking fixation and saccade data,
+        measured with an Eyelink (SR Research), from 8 participants reading 320
+        embedded target words and invisible boundary (see
+        [Gagl, 2016](https://peerj.com/articles/2467/)).
+
+        [BIDS dataset](https://zenodo.org/records/1228659)
+
+    -   Combined behavior and eye-tracking position and pupil data, measured with
+        an Eyelink (SR Research), from 26 participants performing a
+        binocular rivalry task (see
+        [Brascamp et.al, 2021](https://doi.org/10.7554/eLife.66161)).
+
+        [BIDS dataset](https://doi.org/10.5061/dryad.41ns1rncp)
+
+    -   Combined resting-state fMRI and eye-tracking data, measured with an Eyelink
+        (SR research), from 20 participants keeping their gaze steady at the
+        screen center.
+
+        [BIDS dataset](https://openneuro.org/datasets/ds004158/versions/2.0.1)
+
+Setting `PhysioType` to the keyword `"eyetrack"` specifies that
+the physiological recordings in the `<matches>_physio.tsv.gz` have
+been acquired with an *eye-tracker*.
+In the following, *eye-tracker* refers to the apparatus allowing
+the recording of gaze position and/or pupil size.
+
+Eye-tracking data MUST be stored following the general specifications
+for `"generic"` physiological recordings.
+However, it is REQUIRED that recordings corresponding to each eye
+(and/or *cyclopean* or averaged signals for binocular eye-trackers providing
+a third recording) are split into files with different
+[`recording-<label>`](../appendices/entities.md#recording).
+Therefore, the use of [`recording-<label>`](../appendices/entities.md#recording)
+is REQUIRED with eye-tracking data.
+The values `"eye1"`, `"eye2"`, and `"eye3"` are RECOMMENDED as the respective labels
+for the [`recording-<label>`](../appendices/entities.md#recording) entity.
+
+!!! danger "MANDATORY metadata"
+
+    The correspondence of labels and the recorded eye MUST be encoded
+    by the MANDATORY `RecordedEye` metadata.
+
+    The [`recording-<label>`](../appendices/entities.md#recording) entity
+    MAY take other values such as `"left"`, `"cyclopean"`, or `"right"` corresponding
+    to the `RecordedEye` metadata.
+    However, it is RECOMMENDED that metadata is not encoded in the file names to avert
+    that filename and metadata enter into conflict.
+    For example, if [`recording-<label>`](../appendices/entities.md#recording) takes
+    the value `"left"` but the corresponding sidecar JSON file contains a definition of
+    `RecordedEye` being `"right"`.
+
+Eye-tracking files `<matches>_recording-<label>_physio.tsv.gz` MUST follow
+specific column specifications:
+
+<!--
+This block generates a columns table.
+The definitions of these fields can be found in
+  src/schema/rules/tabular_data/eyetrack.yaml
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_columns_table("physio.PhysioEyeTracking") }}
+
+The following table specifies metadata fields for the
+`<matches>_recording-<label>_physio.json` file:
+
+<!-- This block generates a metadata table.
+These tables are defined in
+  src/schema/rules/sidecars
+The definitions of the fields specified in these tables may be found in
+  src/schema/objects/metadata.yaml
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_sidecar_table([
+    "continuous.Continuous",
+    "continuous.PhysioHardware",
+    "continuous.PhysioTypeRequired",
+    "continuous.EyeTrack"
+]) }}
+
+Comprehensively documenting the calibration metadata is RECOMMENDED.
+
+Eye-tracking files `<matches>_recording-<label>_physio.tsv.gz` MAY be annotated
+with a corresponding `<matches>_recording-<label>_physioevents.tsv.gz` file.
+The `<matches>_recording-<label>_physioevents.tsv.gz` file MAY be employed to
+record discontinuous model parameters generated by the eye-tracker, for example,
+those derived from the saccade and blinks model some eye-trackers produce.
+
+**Examples**.
+The recordings produced by a monocular eye-tracker during a
+visual search task may display the following structure:
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-visualSearch_bold.json": "",
+      "sub-01_task-visualSearch_bold.nii.gz": "",
+      "sub-01_task-visualSearch_events.json": "",
+      "sub-01_task-visualSearch_events.tsv": "",
+      "sub-01_task-visualSearch_recording-eye1_physio.json": "",
+      "sub-01_task-visualSearch_recording-eye1_physio.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye1_physioevents.json": "",
+      "sub-01_task-visualSearch_recording-eye1_physioevents.tsv.gz": ""
+    },
+  },
+}) }}
+
+The above example is extended to a binocular eye-tracker producing three signals
+(left and right eyes, plus a *cyclopean* recording), as follows:
+<!-- This block generates a file tree.
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_filetree_example({
+  "sub-01": {
+    "func": {
+      "sub-01_task-visualSearch_bold.json": "",
+      "sub-01_task-visualSearch_bold.nii.gz": "",
+      "sub-01_task-visualSearch_events.json": "",
+      "sub-01_task-visualSearch_events.tsv": "",
+      "sub-01_task-visualSearch_recording-eye1_physio.json": "",
+      "sub-01_task-visualSearch_recording-eye1_physio.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye1_physioevents.json": "",
+      "sub-01_task-visualSearch_recording-eye1_physioevents.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye2_physio.json": "",
+      "sub-01_task-visualSearch_recording-eye2_physio.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye2_physioevents.json": "",
+      "sub-01_task-visualSearch_recording-eye2_physioevents.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye3_physio.json": "",
+      "sub-01_task-visualSearch_recording-eye3_physio.tsv.gz": "",
+      "sub-01_task-visualSearch_recording-eye3_physioevents.json": "",
+      "sub-01_task-visualSearch_recording-eye3_physioevents.tsv.gz": ""
+    },
+  },
+}) }}
+
+Given the above example file structures, a corresponding
+`sub-01_task-visualSearch_recording-eye1_physio.json` sidecar
+could read:
+
+```JSON
+{
+    "DeviceSerialNumber": "17535483",
+    "Columns": ["timestamp", "x_coordinate", "y_coordinate", "pupil_size"],
+    "EnvironmentCoordinates": "top-left",
+    "Manufacturer": "SR-Research",
+    "ManufacturersModelName": "EYELINK II CL v4.56 Aug 18 2010",
+    "RecordedEye": "right",
+    "SampleCoordinateSystem": "gaze-on-screen",
+    "SampleCoordinateUnits": "pixel",
+    "SamplingFrequency": 1000,
+    "SoftwareVersion": "SREB1.10.1630 WIN32 LID:F2AE011 Mod:2017.04.21 15:19 CEST",
+    "ScreenAOIDefinition": [
+        "square",
+        [100, 150, 300, 350]
+    ],
+    "pupil_size": {
+        "Description": "Pupil area of the recorded eye as calculated by the eye-tracker in arbitrary units (see EyeLink's documentation for conversion).",
+        "Units": "a.u."
+    },
+    "timestamp": {
+        "Description": "a continuously increasing identifier of the sampling time registered by the device",
+        "Units": "ms",
+        "Origin": "System startup"
+    }
+}
+```
+
+Content of `sub-01_task-VisualSearch_events.json`:
+
+```JSON
+{
+   "TaskName": "Visual Search",
+   "InstitutionName": "Stanford University",
+   "InstitutionAddress": "450 Serra Mall, Stanford, CA 94305-2004, USA",
+   "StimulusPresentation": {
+       "ScreenDistance": 60,
+       "ScreenRefreshRate": 60,
+       "ScreenResolution": [1024, 768],
+       "ScreenSize": [0.386, 0.29]
    }
-) }}
+}
+```
+
+**Example eye-tracking recording**.
+Given the above `sub-01_task-visualSearch_recording-eye1_physio.json` metadata
+specification, the decompressed content of the
+`sub-01_task-visualSearch_recording-eye1_physio.tsv.gz` can be:
+
+```TSV
+7186799    416.29    267.39    4612.0
+7186800    416.29    268.10    4623.0
+7186801    416.20    269.00    4623.0
+7186802    415.89    269.60    4613.0
+7186803    415.70    269.20    4603.0
+7186804    415.60    266.79    4591.0
+7186805    415.79    264.60    4589.0
+7186806    416.10    263.89    4587.0
+7186807    416.29    265.20    4587.0
+7186808    416.39    266.50    4588.0
+7186809    416.50    266.79    4594.0
+7186810    416.50    267.20    4599.0
+7186811    416.10    268.00    4609.0
+7186812    415.70    268.29    4612.0
+7186813    416.00    268.60    4605.0
+```
+
+Example `sub-01_task-visualSearch_recording-eye1_physioevents.tsv.gz` corresponding
+to the above eye-tracking recording, after decompressing:
+
+```TSV
+7184392    n/a    n/a         n/a    "NO Reply is disabled for function eyelink_cal_result"
+7184392    n/a    n/a         n/a    "RECCFG CR 1000 2 0 R"
+7184392    n/a    n/a         n/a    "ELCLCFG TOWER"
+7186771    n/a    n/a         n/a    "First task trigger"
+7186806    72     fixation    0      n/a
+7186879    231    saccade     1      n/a
+7187111    6186   fixation    0      n/a
+7193298    216    saccade     1      n/a
+7193515    1286   fixation    0      n/a
+7194802    24     saccade     0      n/a
+7194827    2403   fixation    0      n/a
+7197231    17     saccade     0      n/a
+7197249    1640   fixation    0      n/a
+7198890    6      saccade     0      n/a
+7198897    1105   fixation    0      n/a
+7200003    233    saccade     1      n/a
+7200237    184    fixation    0      n/a
+7200422    15     saccade     0      n/a
+7200438    264    fixation    0      n/a
+```
+
+where the first three rows are logged by the eye-tracker and the fourth row shows
+a *message* asynchronously received by the eye-tracker.
+The remainder of the rows contain a subset of parameters registered by the device,
+derived from applying a model to identify saccades and blinks.
+The corresponding `sub-01_task-visualSearch_recording-eye1_physioevents.json` sidecar
+would read:
+
+```JSON
+{
+    "Columns": ["onset", "duration", "trial_type", "blink", "message"],
+    "Description": "Messages logged by the measurement device",
+    "ForeignIndexColumn": "timestamp",
+    "blink": {
+      "Description": "Gives status of the eye.",
+      "Levels": {
+          "0": "Indicates if the eye was open.",
+          "1": "Indicates if the eye was closed.",
+      },
+    },
+    "message": {
+      "Description": "String messages logged by the eye-tracker."
+    },
+    "trial_type": {
+      "Description": "Event type as identified by the eye-tracker's model.",
+      "Levels": {
+          "fixation": "Indicates a fixation.",
+          "saccade": "Indicates a saccade.",
+      },
+    }
+}
+```
diff --git a/src/modality-specific-files/task-events.md b/src/modality-specific-files/task-events.md
index 7dd53428a6..a251fdb9c2 100644
--- a/src/modality-specific-files/task-events.md
+++ b/src/modality-specific-files/task-events.md
@@ -267,6 +267,19 @@ and a guide for using macros can be found at
 -->
 {{ MACROS___make_subobject_table("metadata.StimulusPresentation") }}
 
+!!! warning "Important"
+
+    Some metadata of the `StimulusPresentation` object become REQUIRED with the presence of
+    [eye-tracking data](physiological-recordings.md#eye-tracking)
+
+    The following fields pertaining to `<matches>_events.json` of tasks that were acquired
+    with the simultaneous recording of eye-tracking escalate to REQUIRED as they are considered
+    essential in eye-tracking data analysis:
+
+    -   `ScreenSize`,
+    -   `ScreenResolution`,
+    -   `ScreenDistance`.
+
 The operating system description SHOULD include the following attributes:
 
 -   type (for example, Windows, macOS, Linux)
diff --git a/src/schema/objects/columns.yaml b/src/schema/objects/columns.yaml
index 16422d7beb..77dd5917ff 100644
--- a/src/schema/objects/columns.yaml
+++ b/src/schema/objects/columns.yaml
@@ -162,6 +162,34 @@ duration:
   type: number
   unit: s
   minimum: 0
+x_coordinate:
+  name: x_coordinate
+  display_name: Gaze x-coordinate
+  description: |
+    Gaze position x-coordinate of the recorded eye, in the coordinate
+    units specified in the corresponding metadata sidecar.
+  type: number
+y_coordinate:
+  name: y_coordinate
+  display_name: Gaze y-coordinate
+  description: |
+    Gaze position y-coordinate of the recorded eye, in the coordinate
+    units specified in the corresponding metadata sidecar.
+  type: number
+pupil_size:
+  name: pupil_size
+  display_name: Pupil size
+  description: |
+    Pupil size or area of the recorded eye, in the
+    units specified in the corresponding metadata sidecar.
+  type: number
+et_timestamp:
+  name: timestamp
+  display_name: Eye-tracking recording timestamp
+  description: |
+    Timestamp issued by the eye-tracker indexing the continuous recordings corresponding to
+    the sampled eye.
+  type: number
 filename:
   name: filename
   display_name: Filename
@@ -273,6 +301,13 @@ mapping:
   description: |
     Corresponding integer label in the standard BIDS label lookup.
   type: integer
+message:
+  name: message
+  display_name: Message
+  description: |
+    Brief free-text description of a message (for example in a log generated
+    by a device), or other information of interest.
+  type: string
 material:
   name: material
   display_name: Electrode material
diff --git a/src/schema/objects/enums.yaml b/src/schema/objects/enums.yaml
index 6c43592c9f..0843cc6ae8 100644
--- a/src/schema/objects/enums.yaml
+++ b/src/schema/objects/enums.yaml
@@ -1418,3 +1418,13 @@ microvascular:
   display_name: microvascular
   description: |
     The origin of a tissue: microvascular
+PhysioTypeGeneric:
+  value: generic
+  display_name: Generic Physiological Recording
+  description: |
+    Unspecified physiological recording.
+PhysioTypeEyetrack:
+  value: eyetrack
+  display_name: Eye-tracking recording
+  description: |
+    A specific physiological recording type: eye-tracking.
diff --git a/src/schema/objects/metadata.yaml b/src/schema/objects/metadata.yaml
index f2c3b25c74..0bd60ac065 100644
--- a/src/schema/objects/metadata.yaml
+++ b/src/schema/objects/metadata.yaml
@@ -212,6 +212,14 @@ Authors:
   type: array
   items:
     type: string
+AverageCalibrationError:
+  name: AverageCalibrationError
+  display_name: Average Calibration Error
+  description: |
+    Average calibration error in visual degree. If both eyes recorded, first array
+    corresponds to the left eye and the second to the right eye.
+  type: number
+  unit: degree
 B0FieldIdentifier:
   name: B0FieldIdentifier
   display_name: B0 Field Identifier
@@ -386,6 +394,47 @@ BrainLocation:
     or layer to refer to layer-specific gene expression,
     which can also tie up with laminar fMRI.
   type: string
+CalibrationCount:
+  name: CalibrationCount
+  display_name: Calibration Count
+  description: |
+    The number of calibrations corresponding to this run.
+  type: integer
+  minimum: 0
+CalibrationPosition:
+  name: CalibrationPosition
+  display_name: Calibration Position
+  description: |
+    A list of `[x, y]` coordinates in the `CalibrationUnit`.
+    For example, using 5 positions calibration presented on an HD screen,
+    it could be `[[960,50],[960,540],[960,1030],[50,540],[1870,540]]`.
+  anyOf:
+    - type: array
+      items:
+        type: array
+        minItems: 2
+        maxItems: 2
+        items:
+          type: number
+CalibrationType:
+  name: CalibrationType
+  display_name: Calibration Type
+  description: |
+    The type of the calibration procedure executed last.
+    For example the `"H3"` for horizontal calibration with 3 positions
+    or `"HV9"` for horizontal and vertical calibration with 9 positions,
+    or one point calibration.
+  type: string
+CalibrationUnit:
+  name: CalibrationUnit
+  display_name: Calibration Unit
+  description: |
+    Unit of `"CalibrationPosition"`.
+  type: string
+  enum:
+    - pixel
+    - mm
+    - cm
 CASLType:
   name: CASLType
   display_name: CASL Type
@@ -1074,6 +1123,14 @@ ElectrodeManufacturersModelName:
     If different electrode types are used,
     please use the corresponding table in the `_electrodes.tsv` file.
   type: string
+EnvironmentCoordinates:
+  name: EnvironmentCoordinates
+  display_name: Environment Coordinates
+  description: |
+    Coordinates origin (or zero), for gaze-on-screen coordinates,
+    this can be for example: `"top-left"` or `"center"`.
+    For virtual reality this could be, amongst others, spherical coordinates.
+  type: string
 EncodingTechnique:
   name: EncodingTechnique
   display_name: Encoding Technique
@@ -1113,6 +1170,64 @@ EthicsApprovals:
   type: array
   items:
     type: string
+EventIdentifier:
+  name: EventIdentifier
+  display_name: Event Identifier
+  description: |
+    The message sent to the eye-tracker which disambiguates the belonging
+    of the sample to a certain event, condition or group.
+    This can be a unique trial identifier, or in the case of
+    continuous presentation (for example video) the annotated event of interest.
+  type: string
+EyeCameraSettings:
+  name: EyeCameraSettings
+  display_name: Eye Camera Settings
+  description: |
+    A field to store any settings that influence the resolution
+    and quality of the eye imagery.
+    Autowhitebalance? Changes in sharpness?
+  type: object
+  items:
+    type: object
+EyeTrackerDistance:
+  name: EyeTrackerDistance
+  display_name: Eye-Tracker Distance
+  description: |
+    Distance (in meters) between the eye-tracker and the participant eye(s).
+    Distance can either be expressed as a single numeric value indicating the shortest distance
+    between the participant's eye and the eye-tracker's camera, or a three-coordinates array
+    indicating the X, Y, Z distances between the participant's eye and the eye-tracker's
+    camera.
+  anyOf:
+    - type: number
+      unit: m
+    - type: array
+      items:
+        type: number
+        unit: m
+      minItems: 3
+      maxItems: 3
+EyeTrackingMethod:
+  name: EyeTrackingMethod
+  display_name: Eye-Tracking Method
+  description: |
+    Method used to track gaze or pupil position:
+    "P–CR" for video based eye-tracking using pupil and corneal reflection;
+    "DPI" for Dual-Purkinje Imaging system, "SSC" for scleral search coils;
+    "EOG" for electro-oculogram; "Limbus" for trackers estimating limbus borders
+    between the iris and sclera; or other.
+    See details here:
+    [10.3758/s13428-021-01762-8](https://doi.org/10.3758/s13428-021-01762-8)
+  type: string
+FeatureDetectionSettings:
+  name: FeatureDetectionSettings
+  display_name: Feature Detection Settings
+  description: |
+    Description of feature detection settings.
+    For example, minimum/maximum pupil size.
+  type: object
+  items:
+    type: object
 FiducialsCoordinateSystem:
   name: FiducialsCoordinateSystem
   display_name: Fiducials Coordinate System
@@ -1198,6 +1313,14 @@ FlipAngle:
         unit: degree
         exclusiveMinimum: 0
         maximum: 360
+ForeignIndexColumn:
+  name: ForeignIndexColumn
+  display_name: Column Name of a Foreign Index
+  description: |
+    An existing column name in an corresponding recoding data TSV file that
+    indexes the `"onset"` column of the present TSV file.
+    For example, `"timestamp"` column.
+  type: string
 FrameDuration:
   name: FrameDuration
   display_name: Frame Duration
@@ -1226,6 +1349,15 @@ Funding:
   type: array
   items:
     type: string
+GazeMappingSettings:
+  name: GazeMappingSettings
+  display_name: Gaze Mapping Settings
+  description: |
+    Description of gaze-mapping settings.
+    For example, threshold on pupil confidence required for gaze mapping.
+  type: object
+  items:
+    type: object
 GeneratedBy:
   name: GeneratedBy
   display_name: Generated By
@@ -2133,6 +2265,13 @@ MaxMovement:
     as measured by the head localisation coils (for example, `4.8`).
   type: number
   unit: mm
+MaximalCalibrationError:
+  name: MaximalCalibrationError
+  display_name: Maximal Calibration Error
+  description: |
+    Maximal calibration error in degrees.
+  type: number
+  unit: degree
 MeasurementToolMetadata:
   name: MeasurementToolMetadata
   display_name: Measurement Tool Metadata
@@ -2587,6 +2726,16 @@ PhotoDescription:
   description: |
     Description of the photo.
   type: string
+PhysioType:
+  name: PhysioType
+  display_name: Physiological Recording Type
+  description: |
+    Defines the specific type of physiological recording.
+    For backwards compatibility, the default value is `"generic"`.
+  type: string
+  enum:
+    - $ref: objects.enums.PhysioTypeGeneric.value
+    - $ref: objects.enums.PhysioTypeEyetrack.value
 PixelSize:
   name: PixelSize
   display_name: Pixel Size
@@ -2730,6 +2879,15 @@ PulseSequenceType:
   description: |
     A general description of the pulse sequence used for the scan.
   type: string
+PupilFitMethod:
+  name: PupilFitMethod
+  display_name: Pupil Fit Method
+  description: |
+    The method employed for fitting the pupil, for example
+    `"centre-of-mass"` or `"ellipse"`.
+    If `"centre-of-mass"` or `"ellipse"` method is used, it is RECOMMENDED to
+    use these exact labels.
+  type: string
 Purity:
   name: Purity
   display_name: Purity
@@ -2746,6 +2904,12 @@ RandomRate:
   type: array
   items:
     type: number
+RawDataFilters:
+  name: RawDataFilters
+  display_name: Raw Data Filters
+  description: |
+    Filter settings applied to eye-movement raw data.
+  type: string
 RawSources:
   name: RawSources
   display_name: Raw Sources
@@ -2848,6 +3012,18 @@ ReconMethodParameterValues:
   type: array
   items:
     type: number
+RecordedEye:
+  name: RecordedEye
+  display_name: Recorded Eye
+  description: |
+    Indicates the eye tracked, for example, `"left"` or `"right"`.
+    It SHOULD be set to `"cyclopean"` for recordings combining both eyes
+    as potentially generated by binocular eye-trackers.
+  type: string
+  enum:
+    - left
+    - right
+    - cyclopean
 RecordingDuration:
   name: RecordingDuration
   display_name: Recording Duration
@@ -3014,6 +3190,26 @@ SEEGChannelCount:
     Number of SEEG channels.
   type: integer
   minimum: 0
+SampleCoordinateSystem:
+  name: SampleCoordinateSystem
+  display_name: Coordinate System of the Gaze Position
+  description: |
+    Coordinate system of the gaze position recordings.
+    Generally eye-tracker are set to use `"gaze-on-screen"` coordinate system but you may use
+    `"eye-in-head"` or `"gaze-in-world"` or other alternatives of your choice.
+    If you use the standard `"gaze-on-screen"`, it is RECOMMENDED to use this
+    exact label.
+  type: string
+SampleCoordinateUnits:
+  name: SampleCoordinateUnits
+  display_name: Sample Coordinate Units
+  description: |
+    Unit of individual samples (`"pixel"`, `"mm"` or `"cm"`) .
+  type: string
+  enum:
+    - pixel
+    - mm
+    - cm
 SampleEmbedding:
   name: SampleEmbedding
   display_name: Sample Embedding
@@ -3209,14 +3405,35 @@ ScatterFraction:
     type: number
     minimum: 0
     maximum: 100
+ScreenAOIDefinition:
+  name: ScreenAOIDefinition
+  display_name: Definition of the eye-tracking Screen Area of Interest
+  description: |
+    A description of the shape of the Screen AOIs and what coordinates are used.
+    `["square", ["x_start", "x_stop", "y_start", "y_stop"]]`
+    Other options:
+    `"custom"/"circle"/"triangle", [["x", "y"], ["x", "y"], ["x", "y"], and so on.]`
+  type: object
+  items:
+    type: object
 ScreenDistance:
   name: ScreenDistance
   display_name: Screen Distance
   description: |
     Distance between the participant's eye and the screen. If no screen was used, use `n/a`.
+    `ScreenDistance` is REQUIRED and MUST NOT be `n/a` when the experiment included simultaneous
+    eye-tracking recordings.
+    Distance can either be expressed as a single numeric value indicating the shortest distance between
+    the participant's eye and the screen, or a three-coordinates array indicating the X, Y, Z distances
+    between the participant's eye and the center of the screen.
   anyOf:
     - type: number
       unit: m
+    - type: array
+      items:
+        type: number
+      minItems: 3
+      maxItems: 3
     - type: string
       enum:
         - n/a
@@ -3234,6 +3451,8 @@ ScreenResolution:
     Screen resolution in pixel
     (for example `[1920, 1200]` for a screen of 1920-width by 1080-height pixels),
     if no screen use `n/a`.
+    `ScreenResolution` is REQUIRED when the experiment included simultaneous eye-tracking
+    recordings.
   anyOf:
     - type: array
       items:
@@ -3250,6 +3469,8 @@ ScreenSize:
     Screen size in m, excluding potential screen borders
     (for example `[0.472, 0.295]` for a screen of 47.2-width by 29.5-height cm),
     if no screen use `n/a`.
+    `ScreenSize` is REQUIRED when the experiment included simultaneous eye-tracking
+    recordings.
   anyOf:
     - type: array
       items:
@@ -3594,6 +3815,12 @@ StartTime:
     where `s` reflects whole seconds, and `.000000` reflects OPTIONAL fractional seconds.
   type: number
   unit: s
+StartTime_eyetrack:
+  name: StartTime
+  display_name: Eye-tracking recording start time
+  description: |
+    Eye-tracking timestamp corresponding to the onset (start) of the run.
+  type: number
 StationName:
   name: StationName
   display_name: Station Name
@@ -3637,6 +3864,12 @@ StimulusPresentation:
       $ref: objects.metadata.SoftwareVersion
     Code:
       $ref: objects.metadata.Code
+StopTime_eyetrack:
+  name: StopTime
+  display_name: Eye-tracking recording stop time
+  description: |
+    Eye-tracking timestamp corresponding to the offset (stop) of the run.
+  type: number
 SubjectArtefactDescription:
   name: SubjectArtefactDescription
   display_name: Subject Artifact Description
diff --git a/src/schema/objects/suffixes.yaml b/src/schema/objects/suffixes.yaml
index 91589b62ff..36e5ddbd12 100644
--- a/src/schema/objects/suffixes.yaml
+++ b/src/schema/objects/suffixes.yaml
@@ -775,6 +775,12 @@ physio:
   display_name: Physiological recording
   description: |
     Physiological recordings such as cardiac and respiratory signals.
+physioevents:
+  value: physioevents
+  display_name: Physiological events and asynchronous data
+  description: |
+    Event timing information corresponding to physiological recordings and other
+    asynchronous data such as messages.
 probseg:
   value: probseg
   display_name: Probabilistic Segmentation
diff --git a/src/schema/rules/files/raw/task.yaml b/src/schema/rules/files/raw/task.yaml
index 812765a063..4daafe0c8f 100644
--- a/src/schema/rules/files/raw/task.yaml
+++ b/src/schema/rules/files/raw/task.yaml
@@ -21,6 +21,7 @@ events:
 timeseries:
   suffixes:
     - physio
+    - physioevents
     - stim
   extensions:
     - .tsv.gz
@@ -41,6 +42,7 @@ timeseries:
 timeseries__mri_no_task:
   suffixes:
     - physio
+    - physioevents
     - stim
   extensions:
     - .tsv.gz
diff --git a/src/schema/rules/sidecars/continuous.yaml b/src/schema/rules/sidecars/continuous.yaml
index 3023427138..61d90ed77d 100644
--- a/src/schema/rules/sidecars/continuous.yaml
+++ b/src/schema/rules/sidecars/continuous.yaml
@@ -19,7 +19,51 @@ PhysioHardware:
   selectors:
     - suffix == "physio"
   fields:
+    DeviceSerialNumber: recommended
     Manufacturer: recommended
     ManufacturersModelName: recommended
     SoftwareVersions: recommended
-    DeviceSerialNumber: recommended
+
+PhysioTypeRecommended:
+  selectors:
+    - suffix == "physio"
+  fields:
+    PhysioType: recommended
+
+PhysioTypeRequired:
+  selectors:
+    - suffix == "physio"
+  fields:
+    PhysioType: required
+
+PhysioEvents:
+  selectors:
+    - suffix == "physioevents"
+  fields:
+    Columns: required
+    Description: recommended
+    ForeignIndexColumn: recommended
+
+# Eye-tracking
+EyeTrack:
+  selectors:
+    - suffix == "physio"
+  fields:
+    EnvironmentCoordinates: required
+    RecordedEye: required
+    SampleCoordinateUnits: required
+    SampleCoordinateSystem: required
+    AverageCalibrationError: recommended
+    CalibrationCount: recommended
+    CalibrationPosition: recommended
+    CalibrationType: recommended
+    CalibrationUnit: recommended
+    EyeCameraSettings: recommended
+    EyeTrackerDistance: recommended
+    EyeTrackingMethod: recommended
+    FeatureDetectionSettings: recommended
+    GazeMappingSettings: recommended
+    MaximalCalibrationError: recommended
+    PupilFitMethod: recommended
+    RawDataFilters: recommended
+    ScreenAOIDefinition: recommended
diff --git a/src/schema/rules/sidecars/events.yaml b/src/schema/rules/sidecars/events.yaml
index abd58db73e..9546842fa2 100644
--- a/src/schema/rules/sidecars/events.yaml
+++ b/src/schema/rules/sidecars/events.yaml
@@ -12,3 +12,13 @@ StimulusPresentation:
   fields:
     StimulusPresentation: recommended
     VisionCorrection: optional
+
+StimulusPresentation_for_eyetracking:
+  selectors:
+    - suffix == "events"
+    - intersects([suffix], ["eyetrack"])
+  fields:
+    StimulusPresentation.ScreenSize: required
+    StimulusPresentation.ScreenResolution: required
+    StimulusPresentation.ScreenDistance: required
+    StimulusPresentation.ScreenRefreshRate: recommended
diff --git a/src/schema/rules/tabular_data/physio.yaml b/src/schema/rules/tabular_data/physio.yaml
index 272c4b7cc0..d54e5422bb 100644
--- a/src/schema/rules/tabular_data/physio.yaml
+++ b/src/schema/rules/tabular_data/physio.yaml
@@ -7,3 +7,29 @@ PhysioColumns:
     respiratory: optional
     trigger: optional
   additional_columns: allowed
+
+PhysioEyeTracking:
+  selectors:
+    - PhysioType == "eyetrack"
+  columns:
+    et_timestamp: recommended
+    x_coordinate: required
+    y_coordinate: required
+    pupil_size: optional
+  initial_columns:
+    - et_timestamp
+    - x_coordinate
+    - y_coordinate
+  additional_columns: allowed
+
+PhysioEventsColumns:
+  selectors:
+    - suffix == "physioevents"
+  columns:
+    onset: required
+    duration: recommended
+    trial_type: optional
+    message: optional
+  additional_columns: allowed
+  initial_columns:
+    - onset
diff --git a/tools/schemacode/bidsschematools/render/text.py b/tools/schemacode/bidsschematools/render/text.py
index ce70ae0ded..d7ba02919c 100644
--- a/tools/schemacode/bidsschematools/render/text.py
+++ b/tools/schemacode/bidsschematools/render/text.py
@@ -294,6 +294,8 @@ def make_filename_template(
     else:
         lt, gt = "&lt;", "&gt;"
 
+    title = kwargs.pop("title", "Template:")
+
     schema = Namespace(filter_schema(schema.to_dict(), **kwargs))
     suffix_key_table = value_key_table(schema.objects.suffixes)
     ext_key_table = value_key_table(schema.objects.extensions)
@@ -425,14 +427,13 @@ def make_filename_template(
                 for extension in sorted(extensions)
             )
 
-    paragraph = "\n".join(lines)
     if pdf_format:
-        codeblock = f"Template:\n```Text\n{paragraph}\n```"
+        lines = [title, "```Text"] + lines + ["```"]
     else:
-        codeblock = (
-            f'Template:\n<div class="highlight"><pre><code>{paragraph}\n</code></pre></div>'
-        )
+        lines[0] = f'<div class="highlight"><pre><code>{lines[0]}'
+        lines = [f"<p>{title}</p>"] + lines + ["</code></pre></div>"]
 
+    codeblock = "\n".join(lines)
     codeblock = codeblock.expandtabs(4)
     codeblock = append_filename_template_legend(codeblock, pdf_format)
     codeblock = codeblock.replace("SPEC_ROOT", utils.get_relpath(src_path))