It's only a macro, it does not create any new symbols in the .so.
Maybe you prefer to have it refixed so that it does not cause problems when other .h files use the same macro names? Anyway, It's too late now, I guess...

I just stumbled upon it while updating the docs. I could add that to the private section there and put a FIXME:0.11 comment into the code.

Let's just deprecate the API which was (presumably) not meant to be exposed (if it was, why does none of the derived eleements use it?) and add some comments to make sure no one uses it. It will be removed in 0.11 automatically then.  If it was indeed meant to be public API we can just add prefixed macros when the need arises:

 2007-08-11  Tim-Philipp Müller  <tim at centricular dot net>

        * docs/libs/gst-plugins-base-libs-sections.txt:
        * gst-libs/gst/rtp/gstbasertpdepayload.c:
        * gst-libs/gst/rtp/gstbasertpdepayload.h:
          Mark as deprecated some macros which were presumably meant to be
          private API and accidentally exposed in the public header file.
          Also actually _init() lock (only works at the moment because the
          struct is zeroed out when created and the initial values in the
          mutex struct are zeroes too). (#459585)