mktemp man page about mkdtemp(3)

[Aleksey Cheusov <vle%gmx.net@localhost>]

mktemp man pages says the following about mkdtemp(3)

    1) STANDARDS:

    The mkstemp() and mkdtemp() functions conform to IEEE Std 1003.1-2004
    (``POSIX.1'') and IEEE Std 1003.1-2008 (``POSIX.1''), respectively.

    2) BUGS:

    The mkdtemp() function is nonstandard and should not be used if
    portability is required.

As I can see mkdtemp(3) is described in POSIX
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdtemp.html

What is the value of BUGS note?