doubt most people will read to the end... Note the use of sys/cdefs.h
for pre-C11 compilers...
I didn't included a note about being compatibile w/ userland since a
C11 feature should be obviously usable in userland...
Suggested by: imp
Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.
Reviewed by: ru
Approved by: philip, ed (mentors)
