diff --git a/PyPDF2/_page.py b/PyPDF2/_page.py
index 26c84dc46..1f37ab6ff 100644
--- a/PyPDF2/_page.py
+++ b/PyPDF2/_page.py
@@ -923,7 +923,7 @@ def compress_content_streams(self):
         if content is not None:
             if not isinstance(content, ContentStream):
                 content = ContentStream(content, self.pdf)
-            self[NameObject(PG.CONTENTS)] = content.flateEncode()
+            self[NameObject(PG.CONTENTS)] = content.flate_encode()
 
     def compressContentStreams(self):
         """
diff --git a/PyPDF2/_reader.py b/PyPDF2/_reader.py
index 6680ca2ac..6fc8bd587 100644
--- a/PyPDF2/_reader.py
+++ b/PyPDF2/_reader.py
@@ -389,7 +389,7 @@ def xmp_metadata(self):
         """
         try:
             self._override_encryption = True
-            return self.trailer[TK.ROOT].getXmpMetadata()
+            return self.trailer[TK.ROOT].xmp_metadata
         finally:
             self._override_encryption = False
 
@@ -729,9 +729,9 @@ def getNamedDestinations(self, tree=None, retval=None):
     @property
     def outlines(self):
         """Read-only property."""
-        return self.get_outlines()
+        return self._get_outlines()
 
-    def get_outlines(self, node=None, outlines=None):
+    def _get_outlines(self, node=None, outlines=None):
         """
         Retrieve the document outline present in the document.
 
@@ -768,7 +768,7 @@ def get_outlines(self, node=None, outlines=None):
             # check for sub-outlines
             if "/First" in node:
                 sub_outlines = []
-                self.get_outlines(node["/First"], sub_outlines)
+                self._get_outlines(node["/First"], sub_outlines)
                 if sub_outlines:
                     outlines.append(sub_outlines)
 
@@ -778,18 +778,33 @@ def get_outlines(self, node=None, outlines=None):
 
         return outlines
 
+    def get_outlines(self, node=None, outlines=None):
+        """
+        .. deprecated:: 1.28.0
+
+            Use the property :py:attr:`outlines` instead.
+        """
+        warnings.warn(
+            "get_outlines will be removed in PyPDF2 2.0.0. "
+            "Use the property :py:attr:`outlines` instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self._get_outlines(node, outlines)
+
     def getOutlines(self, node=None, outlines=None):
         """
         .. deprecated:: 1.28.0
 
-            Use :meth:`get_outlines` instead.
+            Use the property :py:attr:`outlines` instead.
         """
         warnings.warn(
-            "getOutlines will be removed in PyPDF2 2.0.0. Use get_outlines instead.",
+            "getOutlines will be removed in PyPDF2 2.0.0. "
+            "Use the property 'outlines' instead.",
             PendingDeprecationWarning,
             stacklevel=2,
         )
-        return self.get_outlines(node, outlines)
+        return self._get_outlines(node, outlines)
 
     def _get_page_number_by_indirect(self, indirect_ref):
         """Generate _pageId2Num"""
@@ -1073,7 +1088,7 @@ def _get_object_from_stream(self, indirect_reference):
         assert obj_stm["/Type"] == "/ObjStm"
         # /N is the number of indirect objects in the stream
         assert idx < obj_stm["/N"]
-        stream_data = BytesIO(b_(obj_stm.getData()))
+        stream_data = BytesIO(b_(obj_stm.get_data()))
         for i in range(obj_stm["/N"]):
             readNonWhitespace(stream_data)
             stream_data.seek(-1, 1)
@@ -1515,7 +1530,7 @@ def _read_pdf15_xref_stream(self, stream):
         xrefstream = read_object(stream, self)
         assert xrefstream["/Type"] == "/XRef"
         self.cache_indirect_object(generation, idnum, xrefstream)
-        stream_data = BytesIO(b_(xrefstream.getData()))
+        stream_data = BytesIO(b_(xrefstream.get_data()))
         # Index pairs specify the subsections in the dictionary. If
         # none create one subsection that spans everything.
         idx_pairs = xrefstream.get("/Index", [0, xrefstream.get("/Size")])
diff --git a/PyPDF2/_writer.py b/PyPDF2/_writer.py
index f4144ee9f..9db67416a 100644
--- a/PyPDF2/_writer.py
+++ b/PyPDF2/_writer.py
@@ -966,7 +966,7 @@ def add_bookmark_destination(self, dest, parent=None):
             parent = outline_ref
 
         parent = parent.get_object()
-        parent.addChild(dest_ref, self)
+        parent.add_child(dest_ref, self)
 
         return dest_ref
 
@@ -1002,7 +1002,7 @@ def add_bookmark_dict(self, bookmark, parent=None):
             parent = outline_ref
 
         parent = parent.get_object()
-        parent.addChild(bookmark_ref, self)
+        parent.add_child(bookmark_ref, self)
 
         return bookmark_ref
 
@@ -1053,7 +1053,7 @@ def add_bookmark(
         dest = Destination(
             NameObject("/" + title + " bookmark"), page_ref, NameObject(fit), *zoom_args
         )
-        dest_array = dest.getDestArray()
+        dest_array = dest.dest_array
         action.update(
             {NameObject("/D"): dest_array, NameObject("/S"): NameObject("/GoTo")}
         )
@@ -1089,7 +1089,7 @@ def add_bookmark(
         bookmark_ref = self._add_object(bookmark)
 
         parent = parent.get_object()
-        parent.addChild(bookmark_ref, self)
+        parent.add_child(bookmark_ref, self)
 
         return bookmark_ref
 
@@ -1470,7 +1470,7 @@ def add_link(self, pagenum, pagedest, rect, border=None, fit="/Fit", *args):
         dest = Destination(
             NameObject("/LinkName"), page_dest, NameObject(fit), *zoom_args
         )  # TODO: create a better name for the link
-        dest_array = dest.getDestArray()
+        dest_array = dest.dest_array
 
         lnk = DictionaryObject()
         lnk.update(
diff --git a/PyPDF2/filters.py b/PyPDF2/filters.py
index 60051b4b9..207a95281 100644
--- a/PyPDF2/filters.py
+++ b/PyPDF2/filters.py
@@ -553,7 +553,7 @@ def _xobj_to_image(x_object_obj):
     from PyPDF2.constants import GraphicsStateParameters as G
 
     size = (x_object_obj[IA.WIDTH], x_object_obj[IA.HEIGHT])
-    data = x_object_obj.getData()
+    data = x_object_obj.get_data()
     if x_object_obj[IA.COLOR_SPACE] == ColorSpaces.DEVICE_RGB:
         mode = "RGB"
     else:
@@ -564,7 +564,7 @@ def _xobj_to_image(x_object_obj):
             extension = ".png"
             img = Image.frombytes(mode, size, data)
             if G.S_MASK in x_object_obj:  # add alpha channel
-                alpha = Image.frombytes("L", size, x_object_obj[G.S_MASK].getData())
+                alpha = Image.frombytes("L", size, x_object_obj[G.S_MASK].get_data())
                 img.putalpha(alpha)
             img_byte_arr = io.BytesIO()
             img.save(img_byte_arr, format="PNG")
diff --git a/PyPDF2/generic.py b/PyPDF2/generic.py
index e95d0abe6..613e99891 100644
--- a/PyPDF2/generic.py
+++ b/PyPDF2/generic.py
@@ -704,7 +704,8 @@ def setdefault(self, key, value=None):
     def __getitem__(self, key):
         return dict.__getitem__(self, key).get_object()
 
-    def getXmpMetadata(self):
+    @property
+    def xmp_metadata(self):
         """
         Retrieve XMP (Extensible Metadata Platform) data relevant to the
         this object, if available.
@@ -725,15 +726,31 @@ def getXmpMetadata(self):
             self[NameObject("/Metadata")] = metadata
         return metadata
 
+    def getXmpMetadata(self):  # XmpInformation
+        """
+        .. deprecated:: 1.28.3
+            Use :meth:`xmp_metadata` instead.
+        """
+        warnings.warn(
+            "getXmpMetadata will be removed in PyPDF2 2.0.0. "
+            "Use xmp_metadata instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.xmp_metadata
+
     @property
     def xmpMetadata(self):
         """
-        Read-only property that accesses the {@link
-        #DictionaryObject.getXmpData getXmpData} function.
-        <p>
-        Stability: Added in v1.12, will exist for all future v1.x releases.
+        .. deprecated:: 1.28.3
+            Use :meth:`xmp_metadata` instead.
         """
-        return self.getXmpMetadata()
+        warnings.warn(
+            "xmpMetadata will be removed in PyPDF2 2.0.0. Use xmp_metadata instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.xmp_metadata
 
     def write_to_stream(self, stream, encryption_key):
         stream.write(b_("<<\n"))
@@ -888,6 +905,14 @@ def children(self):
             child = child["/Next"]
 
     def addChild(self, child, pdf):
+        warnings.warn(
+            DEPR_MSG.format("addChild", "add_child"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        self.add_child(child, pdf)
+
+    def add_child(self, child, pdf):  # PdfReader
         child_obj = child.get_object()
         child = pdf.getReference(child_obj)
         assert isinstance(child, IndirectObject)
@@ -913,6 +938,14 @@ def addChild(self, child, pdf):
         child_obj[NameObject("/Parent")] = parent_ref
 
     def removeChild(self, child):
+        warnings.warn(
+            DEPR_MSG.format("removeChild", "remove_child"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        self.remove_child(child)
+
+    def remove_child(self, child):
         child_obj = child.get_object()
 
         if NameObject("/Parent") not in child_obj:
@@ -1000,7 +1033,25 @@ def emptyTree(self):
 class StreamObject(DictionaryObject):
     def __init__(self):
         self._data = None
-        self.decodedSelf = None
+        self.decoded_self = None
+
+    @property
+    def decodedSelf(self):
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.decoded_self
+
+    @decodedSelf.setter
+    def decodedSelf(self, value):
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        self.decoded_self = value
 
     def write_to_stream(self, stream, encryption_key):
         self[NameObject(SA.LENGTH)] = NumberObject(len(self._data))
@@ -1026,6 +1077,14 @@ def initializeFromDictionary(data):
         return retval
 
     def flateEncode(self):
+        warnings.warn(
+            DEPR_MSG.format("flateEncode", "flate_encode"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.flate_encode()
+
+    def flate_encode(self):
         if SA.FILTER in self:
             f = self[SA.FILTER]
             if isinstance(f, ArrayObject):
@@ -1044,21 +1103,55 @@ def flateEncode(self):
 
 
 class DecodedStreamObject(StreamObject):
+    def get_data(self):
+        return self._data
+
+    def set_data(self, data):
+        self._data = data
+
     def getData(self):
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
         return self._data
 
     def setData(self, data):
-        self._data = data
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        self.set_data(data)
 
 
 class EncodedStreamObject(StreamObject):
     def __init__(self):
-        self.decodedSelf = None
+        self.decoded_self = None
 
-    def getData(self):
-        if self.decodedSelf:
+    @property
+    def decodedSelf(self):
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.decoded_self
+
+    @decodedSelf.setter
+    def decodedSelf(self, value):
+        warnings.warn(
+            DEPR_MSG.format("decodedSelf", "decoded_self"),
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        self.decoded_self = value
+
+    def get_data(self):
+        if self.decoded_self:
             # cached version of decoded object
-            return self.decodedSelf.getData()
+            return self.decoded_self.get_data()
         else:
             # create decoded object
             decoded = DecodedStreamObject()
@@ -1067,10 +1160,10 @@ def getData(self):
             for key, value in list(self.items()):
                 if key not in (SA.LENGTH, SA.FILTER, SA.DECODE_PARMS):
                     decoded[key] = value
-            self.decodedSelf = decoded
+            self.decoded_self = decoded
             return decoded._data
 
-    def setData(self, data):
+    def set_data(self, data):
         raise PdfReadError("Creating EncodedStreamObject is not currently supported")
 
 
@@ -1084,10 +1177,10 @@ def __init__(self, stream, pdf):
         if isinstance(stream, ArrayObject):
             data = b_("")
             for s in stream:
-                data += b_(s.get_object().getData())
+                data += b_(s.get_object().get_data())
             stream = BytesIO(b_(data))
         else:
-            stream = BytesIO(b_(stream.getData()))
+            stream = BytesIO(b_(stream.get_data()))
         self.__parseContentStream(stream)
 
     def __parseContentStream(self, stream):
@@ -1223,13 +1316,21 @@ def __init__(self, arr):
         # must have four points
         assert len(arr) == 4
         # automatically convert arr[x] into NumberObject(arr[x]) if necessary
-        ArrayObject.__init__(self, [self.ensureIsNumber(x) for x in arr])
+        ArrayObject.__init__(self, [self._ensure_is_number(x) for x in arr])
 
-    def ensureIsNumber(self, value):
+    def _ensure_is_number(self, value):
         if not isinstance(value, (NumberObject, FloatObject)):
             value = FloatObject(value)
         return value
 
+    def ensureIsNumber(self, value):
+        warnings.warn(
+            "ensureIsNumber will be removed in PyPDF2 2.0.0. ",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self._ensure_is_number(value)
+
     def __repr__(self):
         return "RectangleObject(%s)" % repr(list(self))
 
@@ -1323,7 +1424,7 @@ def lower_left(self):
 
     @lower_left.setter
     def lower_left(self, value):
-        self[0], self[1] = [self.ensureIsNumber(x) for x in value]
+        self[0], self[1] = [self._ensure_is_number(x) for x in value]
 
     @property
     def lower_right(self):
@@ -1335,7 +1436,7 @@ def lower_right(self):
 
     @lower_right.setter
     def lower_right(self, value):
-        self[2], self[1] = [self.ensureIsNumber(x) for x in value]
+        self[2], self[1] = [self._ensure_is_number(x) for x in value]
 
     @property
     def upper_left(self):
@@ -1347,7 +1448,7 @@ def upper_left(self):
 
     @upper_left.setter
     def upper_left(self, value):
-        self[0], self[3] = [self.ensureIsNumber(x) for x in value]
+        self[0], self[3] = [self._ensure_is_number(x) for x in value]
 
     @property
     def upper_right(self):
@@ -1359,7 +1460,7 @@ def upper_right(self):
 
     @upper_right.setter
     def upper_right(self, value):
-        self[2], self[3] = [self.ensureIsNumber(x) for x in value]
+        self[2], self[3] = [self._ensure_is_number(x) for x in value]
 
     def getLowerLeft(self):
         warnings.warn(
@@ -1407,7 +1508,7 @@ def setLowerRight(self, value):
             PendingDeprecationWarning,
             stacklevel=2,
         )
-        self[2], self[1] = [self.ensureIsNumber(x) for x in value]
+        self[2], self[1] = [self._ensure_is_number(x) for x in value]
 
     def setUpperLeft(self, value):
         warnings.warn(
@@ -1415,7 +1516,7 @@ def setUpperLeft(self, value):
             PendingDeprecationWarning,
             stacklevel=2,
         )
-        self[0], self[3] = [self.ensureIsNumber(x) for x in value]
+        self[0], self[3] = [self._ensure_is_number(x) for x in value]
 
     def setUpperRight(self, value):
         warnings.warn(
@@ -1423,7 +1524,7 @@ def setUpperRight(self, value):
             PendingDeprecationWarning,
             stacklevel=2,
         )
-        self[2], self[3] = [self.ensureIsNumber(x) for x in value]
+        self[2], self[3] = [self._ensure_is_number(x) for x in value]
 
     @property
     def width(self):
@@ -1517,7 +1618,7 @@ def upperRight(self, value):
 class Field(TreeObject):
     """
     A class representing a field dictionary. This class is accessed through
-    :meth:`getFields()<PyPDF2.PdfReader.getFields>`
+    :meth:`get_fields()<PyPDF2.PdfReader.get_fields>`
     """
 
     def __init__(self, data):
@@ -1541,10 +1642,24 @@ def __init__(self, data):
                 pass
 
     @property
-    def fieldType(self):
+    def field_type(self):
         """Read-only property accessing the type of this field."""
         return self.get("/FT")
 
+    @property
+    def fieldType(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`field_type` instead.
+        """
+        warnings.warn(
+            "fieldType will be removed in PyPDF2 2.0.0. "
+            "Use the field_type property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.field_type
+
     @property
     def parent(self):
         """Read-only property accessing the parent of this field."""
@@ -1561,19 +1676,47 @@ def name(self):
         return self.get("/T")
 
     @property
-    def altName(self):
+    def alternate_name(self):
         """Read-only property accessing the alternate name of this field."""
         return self.get("/TU")
 
     @property
-    def mappingName(self):
+    def altName(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`alternate_name` instead.
+        """
+        warnings.warn(
+            "altName will be removed in PyPDF2 2.0.0. "
+            "Use the alternate_name property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.alternate_name
+
+    @property
+    def mapping_name(self):
         """
         Read-only property accessing the mapping name of this field. This
         name is used by PyPDF2 as a key in the dictionary returned by
-        :meth:`getFields()<PyPDF2.PdfReader.getFields>`
+        :meth:`get_fields()<PyPDF2.PdfReader.get_fields>`
         """
         return self.get("/TM")
 
+    @property
+    def mappingName(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`mapping_name` instead.
+        """
+        warnings.warn(
+            "mappingName will be removed in PyPDF2 2.0.0. "
+            "Use the mapping_name property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.mapping_name
+
     @property
     def flags(self):
         """
@@ -1591,12 +1734,26 @@ def value(self):
         return self.get("/V")
 
     @property
-    def defaultValue(self):
+    def default_value(self):
         """Read-only property accessing the default value of this field."""
         return self.get("/DV")
 
     @property
-    def additionalActions(self):
+    def defaultValue(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`default_value` instead.
+        """
+        warnings.warn(
+            "defaultValue will be removed in PyPDF2 2.0.0. "
+            "Use the default_value property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.default_value
+
+    @property
+    def additional_actions(self):
         """
         Read-only property accessing the additional actions dictionary.
         This dictionary defines the field's behavior in response to trigger events.
@@ -1604,6 +1761,20 @@ def additionalActions(self):
         """
         self.get("/AA")
 
+    @property
+    def additionalActions(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`additional_actions` instead.
+        """
+        warnings.warn(
+            "additionalActions will be removed in PyPDF2 2.0.0. "
+            "Use the additional_actions property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.additional_actions
+
 
 class Destination(TreeObject):
     """
@@ -1670,7 +1841,8 @@ def __init__(self, title, page, typ, *args):
         else:
             raise PdfReadError("Unknown Destination Type: %r" % typ)
 
-    def getDestArray(self):
+    @property
+    def dest_array(self):
         return ArrayObject(
             [self.raw_get("/Page"), self["/Type"]]
             + [
@@ -1680,12 +1852,25 @@ def getDestArray(self):
             ]
         )
 
+    def getDestArray(self):
+        """
+        .. deprecated:: 1.28.3
+            Use :py:attr:`dest_array` instead.
+        """
+        warnings.warn(
+            "getDestArray will be removed in PyPDF2 2.0.0. "
+            "Use the dest_array property instead.",
+            PendingDeprecationWarning,
+            stacklevel=2,
+        )
+        return self.dest_array
+
     def write_to_stream(self, stream, encryption_key):
         stream.write(b_("<<\n"))
         key = NameObject("/D")
         key.write_to_stream(stream, encryption_key)
         stream.write(b_(" "))
-        value = self.getDestArray()
+        value = self.dest_array
         value.write_to_stream(stream, encryption_key)
 
         key = NameObject("/S")
@@ -1786,7 +1971,7 @@ def write_to_stream(self, stream, encryption_key):
         key = NameObject("/Dest")
         key.write_to_stream(stream, encryption_key)
         stream.write(b_(" "))
-        value = self.getDestArray()
+        value = self.dest_array
         value.write_to_stream(stream, encryption_key)
         stream.write(b_("\n"))
         stream.write(b_(">>"))
diff --git a/PyPDF2/merger.py b/PyPDF2/merger.py
index 80e70379e..f9f29f442 100644
--- a/PyPDF2/merger.py
+++ b/PyPDF2/merger.py
@@ -29,7 +29,7 @@
 from sys import version_info
 
 from PyPDF2._reader import PdfReader
-from PyPDF2._utils import _isString, DEPR_MSG, str_
+from PyPDF2._utils import DEPR_MSG, _isString, str_
 from PyPDF2._writer import PdfWriter
 from PyPDF2.constants import PagesAttributes as PA
 from PyPDF2.generic import *
@@ -177,7 +177,7 @@ def merge(
 
         outline = []
         if import_bookmarks:
-            outline = reader.get_outlines()
+            outline = reader.outlines
             outline = self._trim_outline(reader, outline, pages)
 
         if bookmark:
@@ -272,7 +272,7 @@ def close(self):
         usage.
         """
         self.pages = []
-        for fo, _pdfr, mine in self.inputs:
+        for fo, _reader, mine in self.inputs:
             if mine:
                 fo.close()
 
@@ -639,7 +639,7 @@ def add_bookmark(
         dest = Destination(
             NameObject("/" + title + " bookmark"), page_ref, NameObject(fit), *zoom_args
         )
-        dest_array = dest.getDestArray()
+        dest_array = dest.dest_array
         action.update(
             {NameObject("/D"): dest_array, NameObject("/S"): NameObject("/GoTo")}
         )
@@ -674,7 +674,7 @@ def add_bookmark(
 
         bookmark_ref = self.output._add_object(bookmark)
         parent = parent.get_object()
-        parent.addChild(bookmark_ref, self.output)
+        parent.add_child(bookmark_ref, self.output)
 
         return bookmark_ref
 
@@ -747,7 +747,7 @@ def add(self, title, pagenum):
 
         self.pdf._addObject(bookmark)
 
-        self.tree.addChild(bookmark)
+        self.tree.add_child(bookmark)
 
     def removeAll(self):
         for child in self.tree.children():
diff --git a/PyPDF2/xmp.py b/PyPDF2/xmp.py
index ed0d6c931..d66cca8e7 100644
--- a/PyPDF2/xmp.py
+++ b/PyPDF2/xmp.py
@@ -58,12 +58,12 @@
 class XmpInformation(PdfObject):
     """
     An object that represents Adobe XMP metadata.
-    Usually accessed by :meth:`getXmpMetadata()<PyPDF2.PdfReader.getXmpMetadata>`
+    Usually accessed by :py:attr:`xmp_metadata()<PyPDF2.PdfReader.xmp_metadata>`
     """
 
     def __init__(self, stream):
         self.stream = stream
-        doc_root = parseString(self.stream.getData())
+        doc_root = parseString(self.stream.get_data())
         self.rdfRoot = doc_root.getElementsByTagNameNS(RDF_NAMESPACE, "RDF")[0]
         self.cache = {}
 
@@ -100,6 +100,8 @@ def getElement(self, aboutUri, namespace, name):
         """
         warnings.warn(
             DEPR_MSG.format("getElement", "get_element"),
+            PendingDeprecationWarning,
+            stacklevel=2,
         )
         return self.get_element(aboutUri, namespace, name)
 
@@ -122,6 +124,8 @@ def getNodesInNamespace(self, aboutUri, namespace):
         """
         warnings.warn(
             DEPR_MSG.format("getNodesInNamespace", "get_nodes_in_namespace"),
+            PendingDeprecationWarning,
+            stacklevel=2,
         )
         return self.get_nodes_in_namespace(aboutUri, namespace)
 
@@ -166,7 +170,7 @@ def get(self):
             if cached:
                 return cached
             retval = []
-            for element in self.getElement("", namespace, name):
+            for element in self.get_element("", namespace, name):
                 bags = element.getElementsByTagNameNS(RDF_NAMESPACE, "Bag")
                 if len(bags):
                     for bag in bags:
diff --git a/Tests/bench.py b/Tests/bench.py
index b2416b724..f881bf4c0 100644
--- a/Tests/bench.py
+++ b/Tests/bench.py
@@ -25,7 +25,7 @@ def page_ops(pdf_path, password):
     page.scale(2, 2)
     page.scaleBy(0.5)
     page.scaleTo(100, 100)
-    page.compressContentStreams()
+    page.compress_content_streams()
     page.extract_text()
 
 
@@ -44,40 +44,42 @@ def merge():
     pdf_forms = os.path.join(RESOURCE_ROOT, "pdflatex-forms.pdf")
     pdf_pw = os.path.join(RESOURCE_ROOT, "libreoffice-writer-password.pdf")
 
-    file_merger = PyPDF2.PdfMerger()
+    merger = PyPDF2.PdfMerger()
 
     # string path:
-    file_merger.append(pdf_path)
-    file_merger.append(outline)
-    file_merger.append(pdf_path, pages=PyPDF2.pagerange.PageRange(slice(0, 0)))
-    file_merger.append(pdf_forms)
+    merger.append(pdf_path)
+    merger.append(outline)
+    merger.append(pdf_path, pages=PyPDF2.pagerange.PageRange(slice(0, 0)))
+    merger.append(pdf_forms)
 
     # Merging an encrypted file
-    pdfr = PyPDF2.PdfReader(pdf_pw)
-    pdfr.decrypt("openpassword")
-    file_merger.append(pdfr)
+    reader = PyPDF2.PdfReader(pdf_pw)
+    reader.decrypt("openpassword")
+    merger.append(reader)
 
     # PdfReader object:
-    file_merger.append(PyPDF2.PdfReader(pdf_path, "rb"), bookmark=True)
+    merger.append(PyPDF2.PdfReader(pdf_path, "rb"), bookmark=True)
 
     # File handle
     with open(pdf_path, "rb") as fh:
-        file_merger.append(fh)
+        merger.append(fh)
 
-    bookmark = file_merger.add_bookmark("A bookmark", 0)
-    file_merger.add_bookmark("deeper", 0, parent=bookmark)
-    file_merger.add_metadata({"author": "Martin Thoma"})
-    file_merger.add_named_destionation("title", 0)
-    file_merger.set_page_layout("/SinglePage")
-    file_merger.set_page_mode("/UseThumbs")
+    bookmark = merger.add_bookmark("A bookmark", 0)
+    merger.add_bookmark("deeper", 0, parent=bookmark)
+    merger.add_metadata({"author": "Martin Thoma"})
+    merger.add_named_destionation("title", 0)
+    merger.set_page_layout("/SinglePage")
+    merger.set_page_mode("/UseThumbs")
 
     tmp_path = "dont_commit_merged.pdf"
-    file_merger.write(tmp_path)
-    file_merger.close()
+    merger.write(tmp_path)
+    merger.close()
 
     # Check if bookmarks are correct
-    pdfr = PyPDF2.PdfReader(tmp_path)
-    assert [el.title for el in pdfr.get_outlines() if isinstance(el, Destination)] == [
+    reader = PyPDF2.PdfReader(tmp_path)
+    assert [
+        el.title for el in reader._get_outlines() if isinstance(el, Destination)
+    ] == [
         "A bookmark",
         "Foo",
         "Bar",
diff --git a/Tests/test_generic.py b/Tests/test_generic.py
index dc9e1a954..6412c8c0c 100644
--- a/Tests/test_generic.py
+++ b/Tests/test_generic.py
@@ -220,7 +220,7 @@ def test_DictionaryObject_key_is_no_pdfobject():
 
 def test_DictionaryObject_xmp_meta():
     do = DictionaryObject({NameObject("/S"): NameObject("/GoTo")})
-    assert do.xmpMetadata is None
+    assert do.xmp_metadata is None
 
 
 def test_DictionaryObject_value_is_no_pdfobject():
diff --git a/Tests/test_merger.py b/Tests/test_merger.py
index d405223dd..5d35400aa 100644
--- a/Tests/test_merger.py
+++ b/Tests/test_merger.py
@@ -17,40 +17,42 @@ def test_merge():
     pdf_forms = os.path.join(RESOURCE_ROOT, "pdflatex-forms.pdf")
     pdf_pw = os.path.join(RESOURCE_ROOT, "libreoffice-writer-password.pdf")
 
-    file_merger = PyPDF2.PdfMerger()
+    merger = PyPDF2.PdfMerger()
 
     # string path:
-    file_merger.append(pdf_path)
-    file_merger.append(outline)
-    file_merger.append(pdf_path, pages=PyPDF2.pagerange.PageRange(slice(0, 0)))
-    file_merger.append(pdf_forms)
+    merger.append(pdf_path)
+    merger.append(outline)
+    merger.append(pdf_path, pages=PyPDF2.pagerange.PageRange(slice(0, 0)))
+    merger.append(pdf_forms)
 
     # Merging an encrypted file
-    pdfr = PyPDF2.PdfReader(pdf_pw)
-    pdfr.decrypt("openpassword")
-    file_merger.append(pdfr)
+    reader = PyPDF2.PdfReader(pdf_pw)
+    reader.decrypt("openpassword")
+    merger.append(reader)
 
     # PdfReader object:
-    file_merger.append(PyPDF2.PdfReader(pdf_path, "rb"), bookmark=True)
+    merger.append(PyPDF2.PdfReader(pdf_path, "rb"), bookmark=True)
 
     # File handle
     with open(pdf_path, "rb") as fh:
-        file_merger.append(fh)
+        merger.append(fh)
 
-    bookmark = file_merger.add_bookmark("A bookmark", 0)
-    file_merger.add_bookmark("deeper", 0, parent=bookmark)
-    file_merger.add_metadata({"author": "Martin Thoma"})
-    file_merger.add_named_destionation("title", 0)
-    file_merger.set_page_layout("/SinglePage")
-    file_merger.set_page_mode("/UseThumbs")
+    bookmark = merger.add_bookmark("A bookmark", 0)
+    merger.add_bookmark("deeper", 0, parent=bookmark)
+    merger.add_metadata({"author": "Martin Thoma"})
+    merger.add_named_destionation("title", 0)
+    merger.set_page_layout("/SinglePage")
+    merger.set_page_mode("/UseThumbs")
 
     tmp_path = "dont_commit_merged.pdf"
-    file_merger.write(tmp_path)
-    file_merger.close()
+    merger.write(tmp_path)
+    merger.close()
 
     # Check if bookmarks are correct
-    pdfr = PyPDF2.PdfReader(tmp_path)
-    assert [el.title for el in pdfr.get_outlines() if isinstance(el, Destination)] == [
+    reader = PyPDF2.PdfReader(tmp_path)
+    assert [
+        el.title for el in reader._get_outlines() if isinstance(el, Destination)
+    ] == [
         "A bookmark",
         "Foo",
         "Bar",
diff --git a/Tests/test_page.py b/Tests/test_page.py
index d7a86e2f9..89489fad3 100644
--- a/Tests/test_page.py
+++ b/Tests/test_page.py
@@ -71,7 +71,7 @@ def test_page_operations(pdf_path, password):
     page.scale(2, 2)
     page.scaleBy(0.5)
     page.scaleTo(100, 100)
-    page.compressContentStreams()
+    page.compress_content_streams()
     page.extract_text()
 
 
@@ -92,7 +92,7 @@ def test_compress_content_streams(pdf_path, password):
     if password:
         reader.decrypt(password)
     for page in reader.pages:
-        page.compressContentStreams()
+        page.compress_content_streams()
 
 
 def test_page_properties():
diff --git a/Tests/test_reader.py b/Tests/test_reader.py
index ca81f6b50..ed1874307 100644
--- a/Tests/test_reader.py
+++ b/Tests/test_reader.py
@@ -125,7 +125,7 @@ def test_get_attachments(src):
                 annotobj = annotation.get_object()
                 if annotobj[IA.SUBTYPE] == "/FileAttachment":
                     fileobj = annotobj["/FS"]
-                    attachments[fileobj["/F"]] = fileobj["/EF"]["/F"].getData()
+                    attachments[fileobj["/F"]] = fileobj["/EF"]["/F"].get_data()
     return attachments
 
 
@@ -138,7 +138,7 @@ def test_get_attachments(src):
 )
 def test_get_outlines(src, outline_elements):
     reader = PdfReader(src)
-    outlines = reader.get_outlines()
+    outlines = reader._get_outlines()
     assert len(outlines) == outline_elements
 
 
@@ -310,16 +310,16 @@ def test_get_form(src, expected, expected_get_fields):
         for field in fields.values():
             # Just access the attributes
             [
-                field.fieldType,
+                field.field_type,
                 field.parent,
                 field.kids,
                 field.name,
                 field.altName,
-                field.mappingName,
+                field.mapping_name,
                 field.flags,
                 field.value,
-                field.defaultValue,
-                field.additionalActions,
+                field.default_value,
+                field.additional_actions,
             ]
 
 
@@ -505,7 +505,7 @@ def test_read_encrypted_without_decryption():
 def test_get_destination_age_number():
     src = os.path.join(RESOURCE_ROOT, "pdflatex-outline.pdf")
     reader = PdfReader(src)
-    outlines = reader.get_outlines()
+    outlines = reader._get_outlines()
     for outline in outlines:
         if not isinstance(outline, list):
             reader.get_destination_page_number(outline)
@@ -562,13 +562,13 @@ def test_issue604(strict):
         if strict:
             with pytest.raises(PdfReadError) as exc:
                 pdf = PdfReader(f, strict=strict)
-                bookmarks = pdf.get_outlines()
+                bookmarks = pdf._get_outlines()
             if "Unknown Destination" not in exc.value.args[0]:
                 raise Exception("Expected exception not raised")
             return  # bookmarks not correct
         else:
             pdf = PdfReader(f, strict=strict)
-            bookmarks = pdf.get_outlines()
+            bookmarks = pdf._get_outlines()
 
         def getDestPages(x):
             # print(x)
diff --git a/Tests/test_workflows.py b/Tests/test_workflows.py
index 8afbf8301..16f2db538 100644
--- a/Tests/test_workflows.py
+++ b/Tests/test_workflows.py
@@ -59,7 +59,7 @@ def test_PdfReaderJpegImage():
 
         page = reader._get_page(0)
         x_object = page[PG.RESOURCES]["/XObject"].get_object()
-        data = x_object["/Im4"].getData()
+        data = x_object["/Im4"].get_data()
 
         # Compare the text of the PDF to a known source
         assert binascii.hexlify(data).decode() == imagetext, (
diff --git a/docs/user/cropping-and-transforming.md b/docs/user/cropping-and-transforming.md
index edd37e2e7..4962f406c 100644
--- a/docs/user/cropping-and-transforming.md
+++ b/docs/user/cropping-and-transforming.md
@@ -49,7 +49,7 @@ page_box = reader.pages[0]
 page_base.mergeTransformedPage(page_box, Transformation())
 # Write the result back
 writer = PdfWriter()
-writer.addPage(page_base)
+writer.add_page(page_base)
 with open("merged-foo.pdf", "wb") as fp:
     writer.write(fp)
 ```
@@ -71,7 +71,7 @@ op = Transformation().rotate(45)
 page_base.mergeTransformedPage(page_box, op)
 # Write the result back
 writer = PdfWriter()
-writer.addPage(page_base)
+writer.add_page(page_base)
 with open("merged-foo.pdf", "wb") as fp:
     writer.write(fp)
 ```
diff --git a/docs/user/file-size.md b/docs/user/file-size.md
index 17a866bcb..7b4b93df8 100644
--- a/docs/user/file-size.md
+++ b/docs/user/file-size.md
@@ -30,8 +30,8 @@ reader = PyPDF2.PdfReader("example.pdf")
 writer = PyPDF2.PdfWriter()
 
 for page in reader.pages:
-    page.compressContentStreams()
-    writer.addPage(page)
+    page.compress_content_streams()
+    writer.add_page(page)
 
 with open("out.pdf", "wb") as f:
     writer.write(f)
diff --git a/docs/user/reading-pdf-annotations.md b/docs/user/reading-pdf-annotations.md
index 91aa4c76b..8c01fe728 100644
--- a/docs/user/reading-pdf-annotations.md
+++ b/docs/user/reading-pdf-annotations.md
@@ -63,5 +63,5 @@ for page in reader.pages:
             subtype = annot.get_object()["/Subtype"]
             if subtype == "/FileAttachment":
                 fileobj = annotobj["/FS"]
-                attachments[fileobj["/F"]] = fileobj["/EF"]["/F"].getData()
+                attachments[fileobj["/F"]] = fileobj["/EF"]["/F"].get_data()
 ```