+*_count* fields.
+
+**Error indications:** Incorrect data at runtime, crashes. But note that other
+changes in the same version already require regenerating the files and have
+better indications of errors, so this is only an issue for development
+versions.
+
+Renamed some macros and identifiers
+-----------------------------------
+**Rationale:** Some names in nanopb core were badly chosen and conflicted with
+ISO C99 reserved names or lacked a prefix. While they haven't caused trouble
+so far, it is reasonable to switch to non-conflicting names as these are rarely
+used from user code.
+
+**Changes:** The following identifier names have changed:
+
+ * Macros:
+
+ * STATIC_ASSERT(x) -> PB_STATIC_ASSERT(x)
+ * UNUSED(x) -> PB_UNUSED(x)
+
+ * Include guards:
+
+ * _PB_filename_ -> PB_filename_INCLUDED
+
+ * Structure forward declaration tags:
+
+ * _pb_field_t -> pb_field_s
+ * _pb_bytes_array_t -> pb_bytes_array_s
+ * _pb_callback_t -> pb_callback_s
+ * _pb_extension_type_t -> pb_extension_type_s
+ * _pb_extension_t -> pb_extension_s
+ * _pb_istream_t -> pb_istream_s
+ * _pb_ostream_t -> pb_ostream_s
+
+**Required actions:** Regenerate all *.pb.c* files. If you use any of the above
+identifiers in your application code, perform search-replace to the new name.
+
+**Error indications:** Compiler errors on lines with the macro/type names.