typedef naming convention

[divine fallacy]

"Under C convention (such as in the C standard library), types declared
with typedef end with '_t' (e.g., size_t, time_t)."

How rigidly should this be followed? Is there any reason not to follow it?

Mainly interested how sensible the policy is to people with experience.

[Peter87]

POSIX reserves names ending with _t so if you care about POSIX you should not use it.