Why permissions different on different directory with mkdir command ?

[Sammy_2]

I tried to do :
mkdir test
in /users/testuser dir. and SGID is set on the directory.
If I run the same command in another directory like /tmp or /home the the perms are different .(no SUID set). I am executing mkdir as root in both directories.
Why ?

HPUX 11.00

See ex. below
========================
SERVER1::/users/testuser ==> umask
07
SERVER1::/users/testuser ==> id
uid=0(root) gid=3(sys) groups=0(root),1(other),2(bin),4(adm),5(daemon),6(mail),7
(lp),20(users)
SERVER1::/users/testuser ==> mkdir test
SERVER1::/users/testuser ==> ls -ld test
drwxrws--- 2 root testuser 96 Aug 22 10:34 test
SERVER1::/users/testuser ==>


=================================

SERVER1::/tmp ==> mkdir test
SERVER1::/tmp ==> ls -ld test
drwxrwx--- 2 root sys 96 Aug 22 10:34 test
SERVER1::/tmp ==> umask
07
SERVER1::/tmp ==> id
uid=0(root) gid=3(sys) groups=0(root),1(other),2(bin),4(adm),5(daemon),6(mail),7
(lp),20(users)
SERVER1::/tmp ==>

[Stefan Farrelly · Accepted solution]

check the permissions on the directory above;
(on server1) ll -d /users/testuser

It must have SGID on it which is then copied to any subdirs created under it.

[Vitek Pepas]

SGID is derived from parent directory. You have it set for /user/testuser, therefore it's subdirectories will have it, too.

[Sammy_2]

Bingo !!Stefan and Vitek. My mistake. You are right that
/users/testuser have SGID. Should have checked myself.
Much thanks.

[Umapathy S]

Sam,
The parent dir surely has SGID set. Check that out.

-Umapathy