diff --git a/objectivec/GPBUtilities.h b/objectivec/GPBUtilities.h
index 5b55104..5464dfb 100644
--- a/objectivec/GPBUtilities.h
+++ b/objectivec/GPBUtilities.h
@@ -38,24 +38,58 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-// Generates a string that should be a valid "Text Format" for the C++ version
-// of Protocol Buffers. lineIndent can be nil if no additional line indent is
-// needed. The comments provide the names according to the ObjC library, they
-// most likely won't exactly match the original .proto file.
+/**
+ * Generates a string that should be a valid "TextFormat" for the C++ version
+ * of Protocol Buffers.
+ *
+ * @param message    The message to generate from.
+ * @param lineIndent A string to use as the prefix for all lines generated. Can
+ *                   be nil if no extra indent is needed.
+ *
+ * @return An NSString with the TextFormat of the message.
+ **/
 NSString *GPBTextFormatForMessage(GPBMessage *message,
                                   NSString * __nullable lineIndent);
+
+/**
+ * Generates a string that should be a valid "TextFormat" for the C++ version
+ * of Protocol Buffers.
+ *
+ * @param unknownSet The unknown field set to generate from.
+ * @param lineIndent A string to use as the prefix for all lines generated. Can
+ *                   be nil if no extra indent is needed.
+ *
+ * @return An NSString with the TextFormat of the unknown field set.
+ **/
 NSString *GPBTextFormatForUnknownFieldSet(GPBUnknownFieldSet * __nullable unknownSet,
                                           NSString * __nullable lineIndent);
 
-//
-// Test if the given field is set on a message.
-//
+/**
+ * Checks if the given field number is set on a message.
+ *
+ * @param self        The message to check.
+ * @param fieldNumber The field number to check.
+ *
+ * @return YES if the field number is set on the given message.
+ **/
 BOOL GPBMessageHasFieldNumberSet(GPBMessage *self, uint32_t fieldNumber);
+
+/**
+ * Checks if the given field is set on a message.
+ *
+ * @param self  The message to check.
+ * @param field The field to check.
+ *
+ * @return YES if the field is set on the given message.
+ **/
 BOOL GPBMessageHasFieldSet(GPBMessage *self, GPBFieldDescriptor *field);
 
-//
-// Clear the given field of a message.
-//
+/**
+ * Clears the given field for the given message.
+ *
+ * @param self  The message for which to clear the field.
+ * @param field The field to clear.
+ **/
 void GPBClearMessageField(GPBMessage *self, GPBFieldDescriptor *field);
 
 //%PDDM-EXPAND GPB_ACCESSORS()
@@ -63,74 +97,306 @@
 
 
 //
-// Get/Set the given field of a message.
+// Get/Set a given field from/to a message.
 //
 
 // Single Fields
 
+/**
+ * Gets the value of a bytes field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 NSData *GPBGetMessageBytesField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a bytes field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageBytesField(GPBMessage *self, GPBFieldDescriptor *field, NSData *value);
 
+/**
+ * Gets the value of a string field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 NSString *GPBGetMessageStringField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a string field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageStringField(GPBMessage *self, GPBFieldDescriptor *field, NSString *value);
 
+/**
+ * Gets the value of a message field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 GPBMessage *GPBGetMessageMessageField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a message field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageMessageField(GPBMessage *self, GPBFieldDescriptor *field, GPBMessage *value);
 
+/**
+ * Gets the value of a group field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 GPBMessage *GPBGetMessageGroupField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a group field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageGroupField(GPBMessage *self, GPBFieldDescriptor *field, GPBMessage *value);
 
+/**
+ * Gets the value of a bool field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 BOOL GPBGetMessageBoolField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a bool field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageBoolField(GPBMessage *self, GPBFieldDescriptor *field, BOOL value);
 
+/**
+ * Gets the value of an int32 field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 int32_t GPBGetMessageInt32Field(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of an int32 field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageInt32Field(GPBMessage *self, GPBFieldDescriptor *field, int32_t value);
 
+/**
+ * Gets the value of an uint32 field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 uint32_t GPBGetMessageUInt32Field(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of an uint32 field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageUInt32Field(GPBMessage *self, GPBFieldDescriptor *field, uint32_t value);
 
+/**
+ * Gets the value of an int64 field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 int64_t GPBGetMessageInt64Field(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of an int64 field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageInt64Field(GPBMessage *self, GPBFieldDescriptor *field, int64_t value);
 
+/**
+ * Gets the value of an uint64 field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 uint64_t GPBGetMessageUInt64Field(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of an uint64 field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageUInt64Field(GPBMessage *self, GPBFieldDescriptor *field, uint64_t value);
 
+/**
+ * Gets the value of a float field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 float GPBGetMessageFloatField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a float field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageFloatField(GPBMessage *self, GPBFieldDescriptor *field, float value);
 
+/**
+ * Gets the value of a double field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ **/
 double GPBGetMessageDoubleField(GPBMessage *self, GPBFieldDescriptor *field);
+
+/**
+ * Sets the value of a double field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The to set in the field.
+ **/
 void GPBSetMessageDoubleField(GPBMessage *self, GPBFieldDescriptor *field, double value);
 
-// Get/Set the given enum field of a message.  You can only Set values that are
-// members of the enum.  For proto3, when doing a Get, if the value isn't a
-// memeber of the enum, kGPBUnrecognizedEnumeratorValue will be returned. The
-// the functions with "Raw" in the will bypass all checks.
+/**
+ * Gets the given enum field of a message. For proto3, if the value isn't a
+ * member of the enum, @c kGPBUnrecognizedEnumeratorValue will be returned.
+ * GPBGetMessageRawEnumField will bypass the check and return whatever value
+ * was set.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ *
+ * @return The enum value for the given field.
+ **/
 int32_t GPBGetMessageEnumField(GPBMessage *self, GPBFieldDescriptor *field);
-void GPBSetMessageEnumField(GPBMessage *self, GPBFieldDescriptor *field, int32_t value);
+
+/**
+ * Set the given enum field of a message. You can only set values that are
+ * members of the enum.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The enum value to set in the field.
+ **/
+void GPBSetMessageEnumField(GPBMessage *self,
+                            GPBFieldDescriptor *field,
+                            int32_t value);
+
+/**
+ * Get the given enum field of a message. No check is done to ensure the value
+ * was defined in the enum.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The field to get.
+ *
+ * @return The raw enum value for the given field.
+ **/
 int32_t GPBGetMessageRawEnumField(GPBMessage *self, GPBFieldDescriptor *field);
-void GPBSetMessageRawEnumField(GPBMessage *self, GPBFieldDescriptor *field, int32_t value);
+
+/**
+ * Set the given enum field of a message. You can set the value to anything,
+ * even a value that is not a member of the enum.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param value The raw enum value to set in the field.
+ **/
+void GPBSetMessageRawEnumField(GPBMessage *self,
+                               GPBFieldDescriptor *field,
+                               int32_t value);
 
 // Repeated Fields
 
-// The object will/should be GPB*Array or NSMutableArray based on the field's
-// type.
+/**
+ * Gets the value of a repeated field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The repeated field to get.
+ *
+ * @return A GPB*Array or an NSMutableArray based on the field's type.
+ **/
 id GPBGetMessageRepeatedField(GPBMessage *self, GPBFieldDescriptor *field);
-void GPBSetMessageRepeatedField(GPBMessage *self, GPBFieldDescriptor *field, id array);
+
+/**
+ * Sets the value of a repeated field.
+ *
+ * @param self  The message into which to set the field.
+ * @param field The field to set.
+ * @param array A GPB*Array or NSMutableArray based on the field's type.
+ **/
+void GPBSetMessageRepeatedField(GPBMessage *self,
+                                GPBFieldDescriptor *field,
+                                id array);
 
 // Map Fields
 
-// The object will/should be GPB*Dictionary or NSMutableDictionary based on the
-// field's type.
+/**
+ * Gets the value of a map<> field.
+ *
+ * @param self  The message from which to get the field.
+ * @param field The repeated field to get.
+ *
+ * @return A GPB*Dictionary or NSMutableDictionary based on the field's type.
+ **/
 id GPBGetMessageMapField(GPBMessage *self, GPBFieldDescriptor *field);
-void GPBSetMessageMapField(GPBMessage *self, GPBFieldDescriptor *field, id dictionary);
+
+/**
+ * Sets the value of a map<> field.
+ *
+ * @param self       The message into which to set the field.
+ * @param field      The field to set.
+ * @param dictionary A GPB*Dictionary or NSMutableDictionary based on the
+ *                   field's type.
+ **/
+void GPBSetMessageMapField(GPBMessage *self,
+                           GPBFieldDescriptor *field,
+                           id dictionary);
 
 //%PDDM-EXPAND-END GPB_ACCESSORS()
 
-// Returns an empty NSData to assign to byte fields when you wish
-// to assign them to empty. Prevents allocating a lot of little [NSData data]
-// objects.
+/**
+ * Returns an empty NSData to assign to byte fields when you wish to assign them
+ * to empty. Prevents allocating a lot of little [NSData data] objects.
+ **/
 NSData *GPBEmptyNSData(void) __attribute__((pure));
 
+/**
+ * Drops the `unknownFields` from the given message and from all sub message.
+ **/
+void GPBMessageDropUnknownFieldsRecursively(GPBMessage *message);
+
 NS_ASSUME_NONNULL_END
 
 CF_EXTERN_C_END
@@ -139,49 +405,135 @@
 //%PDDM-DEFINE GPB_ACCESSORS()
 //%
 //%//
-//%// Get/Set the given field of a message.
+//%// Get/Set a given field from/to a message.
 //%//
 //%
 //%// Single Fields
 //%
-//%GPB_ACCESSOR_SINGLE_FULL(Bytes, NSData, *)
-//%GPB_ACCESSOR_SINGLE_FULL(String, NSString, *)
-//%GPB_ACCESSOR_SINGLE_FULL(Message, GPBMessage, *)
-//%GPB_ACCESSOR_SINGLE_FULL(Group, GPBMessage, *)
-//%GPB_ACCESSOR_SINGLE(Bool, BOOL)
-//%GPB_ACCESSOR_SINGLE(Int32, int32_t)
-//%GPB_ACCESSOR_SINGLE(UInt32, uint32_t)
-//%GPB_ACCESSOR_SINGLE(Int64, int64_t)
-//%GPB_ACCESSOR_SINGLE(UInt64, uint64_t)
-//%GPB_ACCESSOR_SINGLE(Float, float)
-//%GPB_ACCESSOR_SINGLE(Double, double)
-//%// Get/Set the given enum field of a message.  You can only Set values that are
-//%// members of the enum.  For proto3, when doing a Get, if the value isn't a
-//%// memeber of the enum, kGPBUnrecognizedEnumeratorValue will be returned. The
-//%// the functions with "Raw" in the will bypass all checks.
+//%GPB_ACCESSOR_SINGLE_FULL(Bytes, NSData, , *)
+//%GPB_ACCESSOR_SINGLE_FULL(String, NSString, , *)
+//%GPB_ACCESSOR_SINGLE_FULL(Message, GPBMessage, , *)
+//%GPB_ACCESSOR_SINGLE_FULL(Group, GPBMessage, , *)
+//%GPB_ACCESSOR_SINGLE(Bool, BOOL, )
+//%GPB_ACCESSOR_SINGLE(Int32, int32_t, n)
+//%GPB_ACCESSOR_SINGLE(UInt32, uint32_t, n)
+//%GPB_ACCESSOR_SINGLE(Int64, int64_t, n)
+//%GPB_ACCESSOR_SINGLE(UInt64, uint64_t, n)
+//%GPB_ACCESSOR_SINGLE(Float, float, )
+//%GPB_ACCESSOR_SINGLE(Double, double, )
+//%/**
+//% * Gets the given enum field of a message. For proto3, if the value isn't a
+//% * member of the enum, @c kGPBUnrecognizedEnumeratorValue will be returned.
+//% * GPBGetMessageRawEnumField will bypass the check and return whatever value
+//% * was set.
+//% *
+//% * @param self  The message from which to get the field.
+//% * @param field The field to get.
+//% *
+//% * @return The enum value for the given field.
+//% **/
 //%int32_t GPBGetMessageEnumField(GPBMessage *self, GPBFieldDescriptor *field);
-//%void GPBSetMessageEnumField(GPBMessage *self, GPBFieldDescriptor *field, int32_t value);
+//%
+//%/**
+//% * Set the given enum field of a message. You can only set values that are
+//% * members of the enum.
+//% *
+//% * @param self  The message into which to set the field.
+//% * @param field The field to set.
+//% * @param value The enum value to set in the field.
+//% **/
+//%void GPBSetMessageEnumField(GPBMessage *self,
+//%                            GPBFieldDescriptor *field,
+//%                            int32_t value);
+//%
+//%/**
+//% * Get the given enum field of a message. No check is done to ensure the value
+//% * was defined in the enum.
+//% *
+//% * @param self  The message from which to get the field.
+//% * @param field The field to get.
+//% *
+//% * @return The raw enum value for the given field.
+//% **/
 //%int32_t GPBGetMessageRawEnumField(GPBMessage *self, GPBFieldDescriptor *field);
-//%void GPBSetMessageRawEnumField(GPBMessage *self, GPBFieldDescriptor *field, int32_t value);
+//%
+//%/**
+//% * Set the given enum field of a message. You can set the value to anything,
+//% * even a value that is not a member of the enum.
+//% *
+//% * @param self  The message into which to set the field.
+//% * @param field The field to set.
+//% * @param value The raw enum value to set in the field.
+//% **/
+//%void GPBSetMessageRawEnumField(GPBMessage *self,
+//%                               GPBFieldDescriptor *field,
+//%                               int32_t value);
 //%
 //%// Repeated Fields
 //%
-//%// The object will/should be GPB*Array or NSMutableArray based on the field's
-//%// type.
+//%/**
+//% * Gets the value of a repeated field.
+//% *
+//% * @param self  The message from which to get the field.
+//% * @param field The repeated field to get.
+//% *
+//% * @return A GPB*Array or an NSMutableArray based on the field's type.
+//% **/
 //%id GPBGetMessageRepeatedField(GPBMessage *self, GPBFieldDescriptor *field);
-//%void GPBSetMessageRepeatedField(GPBMessage *self, GPBFieldDescriptor *field, id array);
+//%
+//%/**
+//% * Sets the value of a repeated field.
+//% *
+//% * @param self  The message into which to set the field.
+//% * @param field The field to set.
+//% * @param array A GPB*Array or NSMutableArray based on the field's type.
+//% **/
+//%void GPBSetMessageRepeatedField(GPBMessage *self,
+//%                                GPBFieldDescriptor *field,
+//%                                id array);
 //%
 //%// Map Fields
 //%
-//%// The object will/should be GPB*Dictionary or NSMutableDictionary based on the
-//%// field's type.
+//%/**
+//% * Gets the value of a map<> field.
+//% *
+//% * @param self  The message from which to get the field.
+//% * @param field The repeated field to get.
+//% *
+//% * @return A GPB*Dictionary or NSMutableDictionary based on the field's type.
+//% **/
 //%id GPBGetMessageMapField(GPBMessage *self, GPBFieldDescriptor *field);
-//%void GPBSetMessageMapField(GPBMessage *self, GPBFieldDescriptor *field, id dictionary);
+//%
+//%/**
+//% * Sets the value of a map<> field.
+//% *
+//% * @param self       The message into which to set the field.
+//% * @param field      The field to set.
+//% * @param dictionary A GPB*Dictionary or NSMutableDictionary based on the
+//% *                   field's type.
+//% **/
+//%void GPBSetMessageMapField(GPBMessage *self,
+//%                           GPBFieldDescriptor *field,
+//%                           id dictionary);
 //%
 
-//%PDDM-DEFINE GPB_ACCESSOR_SINGLE(NAME, TYPE)
-//%GPB_ACCESSOR_SINGLE_FULL(NAME, TYPE, )
-//%PDDM-DEFINE GPB_ACCESSOR_SINGLE_FULL(NAME, TYPE, TisP)
+//%PDDM-DEFINE GPB_ACCESSOR_SINGLE(NAME, TYPE, AN)
+//%GPB_ACCESSOR_SINGLE_FULL(NAME, TYPE, AN, )
+//%PDDM-DEFINE GPB_ACCESSOR_SINGLE_FULL(NAME, TYPE, AN, TisP)
+//%/**
+//% * Gets the value of a##AN NAME$L field.
+//% *
+//% * @param self  The message from which to get the field.
+//% * @param field The field to get.
+//% **/
 //%TYPE TisP##GPBGetMessage##NAME##Field(GPBMessage *self, GPBFieldDescriptor *field);
+//%
+//%/**
+//% * Sets the value of a##AN NAME$L field.
+//% *
+//% * @param self  The message into which to set the field.
+//% * @param field The field to set.
+//% * @param value The to set in the field.
+//% **/
 //%void GPBSetMessage##NAME##Field(GPBMessage *self, GPBFieldDescriptor *field, TYPE TisP##value);
 //%