Ugh, that example is pretty bad and I kind of doubt that we even need such overly complicated examples in the guidelines. But the formatting was definitely wrong, and with this patch it renders fine for me.
Pull-Request has been merged by tibbs
(If someone wants to rephrase the guidelines in that regard: Currently, there is zero explanation why in the example for sendmail the removal is moved from %postun to %preun and what the readlink business in (the new) %postun is about.)
%postun
%preun
readlink