New Code (2)!
You may have thought the latest Postoffice beta release was a fairly trivial one. But no, that honor is reserved for discount, which has been pushed up to version 2.0.3 by simply updating the markdown(1) and markdown(3) manpages to correctly describe the thicket of MKD_flags available in the 2.x version of the published interface.
To save the release from being a completely document-based revision, I also tweaked mkd_document() to add a null byte at the end of the generated document buffer. The published interface says that you need to get the length of the generated document from the return code from mkd_document(), but if you treat that buffer as a C string there can be unfortunate side-effects and it’s pretty cheap to concatenate a null onto the end of the buffer before I pass it up to the caller.
So if you don’t use mkd_document() and never read the manpages, this is a complete no-op release. If you do use mkd_document() and want to treat the buffer as a C string, or if you expect the documentation to have some relationship to the code, this is the New Code! that you’ve been looking for, and you should download and install it immediately, if not sooner.