[RFC v6] system_data_types.7: Document types: sigval, ssize_t, suseconds_t, time_t, timer_t, timespec, timeval

[Thorsten Glaser]

Alejandro Colomar dixit:

> POSIX does more or less the same:
> It has a ¿main? header where the type is defined

It does?

When I look at one of the headers, for example…
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_time.h.html
… I see a number of types being defined, but the types don’t have
their own pages nor is described which is the “main” header (the same
goes for constants, e.g. NULL is defined by several headers).

Or is wording like…

     The <stdlib.h> header shall define NULL as described in [10]<stddef.h>.

… where you get the notion of a “main header” from?
If so, where in the standard is this expectation documented?

Curious,
//mirabilos
-- 
“It is inappropriate to require that a time represented as
 seconds since the Epoch precisely represent the number of
 seconds between the referenced time and the Epoch.”
	-- IEEE Std 1003.1b-1993 (POSIX) Section B.2.2.2