OSSL_CALLBACK.pod: add missing info on required return values of callback functions

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28474)

diff --git a/doc/man3/OSSL_CALLBACK.pod b/doc/man3/OSSL_CALLBACK.pod
index 5fa8a8f089161f70c07a2c3b5bf7a1d65baff76e..c0ffad53c99220faf953465395f0e76decc8cc86 100644 (file)
--- a/doc/man3/OSSL_CALLBACK.pod
+++ b/doc/man3/OSSL_CALLBACK.pod
@@ -47,15 +47,10 @@ Additional parameters can be passed with the L<OSSL_PARAM(3)> array I<params>,
 
 =back
 
-=begin comment RETURN VALUES doesn't make sense for a manual that only
-describes a type, but document checkers still want that section, and
-to have more than just the section title.
-
 =head1 RETURN VALUES
 
-txt
-
-=end comment
+Functions of type B<OSSL_CALLBACK> and B<OSSL_PASSPHRASE_CALLBACK>
+must return 1 on success and 0 on failure.
 
 =head1 SEE ALSO