Added diagram to be extra clear about timestamps and offsets.

Minor editorial changes.

asciidoc/volume1/use-cases/tf1-ch-c-use-case-stad.adoc

@@ -312,7 +312,7 @@ NOTE: This requirement supplements TR1340 in <<ref_ieee_11073_10700_2022>>&mdash
 .R1522
 [sdpi_requirement#r1522,sdpi_req_level=shall]
 ****
-When the <<vol1_spec_sdpi_p_actor_somds_provider>> detects a step adjustment of a system clock, used in making its System Function Contribution (<<acronym_sfc>>), the <<vol1_spec_sdpi_p_actor_somds_provider>> shall either:
+When the <<vol1_spec_sdpi_p_actor_somds_provider>> detects an abrupt time adjustment of a system clock, used in making its System Function Contribution (<<acronym_sfc>>), the <<vol1_spec_sdpi_p_actor_somds_provider>> shall either:
 
 * initiate a new MDIB sequence by assigning a new MDIB sequence identifier, or
 * set `pm:ClockState/@ActivationState` to `StndBy` when any timestamp in a <<acronym_mdib>> version was not obtained from the time-reference frame of the active clock in the same version, or 

asciidoc/volume3/biceps-extension-provisions/tf3-ch-8.3.2.9.8-extension-timestamp.adoc

@@ -47,9 +47,13 @@ The clock epoch schema is available in <<vol3_appendix_a_xml_schemas_timestamp_v
 * the state for metric `m1` references epoch version 3; all timestamps in this state are versioned,
 * the timestamp for metric `m2` is not versioned; its timestamp is less than `pm:ClockState/@LastSet` and its value should be treated with greater suspicion than later timestamps, 
 * although the current time (`pm:ClockState/@DateAndTime`) is also less than `pm:ClockState/@LastSet`, the current time is always reported using the current time-reference frame; its value need not be treated with any more suspicion than normal,
-* each `sdpi:Epoch` includes a `@Version`, `@Timestamp` and `@Offset`; the timestamp is in the time-reference frame of the versioned epoch, adding the `@Timestamp` and `@Offset` provides a timestamp for an equivalent point in time for the next epoch version,
+* each `sdpi:Epoch` includes a `@Version`, `@Timestamp` and `@Offset`; the timestamp is in the time-reference frame of the versioned epoch, adding the `@Timestamp` and `@Offset` provides a timestamp for an equivalent point in time for the next epoch version (see illustration below),
 * the default value of any timestamp not specifically versioned is the current epoch version. 
 
+`sdpi:Epoch/@Offset` gives the change in time from the `sdpi:Epoch/@Timestamp` in the previous epoch to an equivalent point in time in the new epoch: 
+
+image::vol3-diagram-biceps-ext-non-slewing_adj.svg[align=center]
+
 .Example MDIB state following two recent non-slewing time adjustments
 [#vol3_example_extension_clock_discontinuities]
 ====