The following version of the protocol document contains significant non-technical editorial changes:
https://www.oasis-open.org/apps/org/workgroup/odata/download.php/48762/odata-core-v4.0-wd01-part1-protocol-current-2013-4-5MP.docx

These changes were made to improve consistency and readability, remove redundancy, and address other editorial issues in the document, and include (but are not limited to)
-ordering http headers alphabetically
-adding missing http headers
-reworded data model section
-added missing error codes (501, 304,...)
-rearranged sections ($select, $expand, $format shouldn't be nested under querying collections)
-moved information on declaring and advertising actions/functions to a common section.

These changes should all be editorial in nature.