users, groups, etc. for posix authentication?

[Christ Schlacta <lists@aarcane.org>]

is there any reason that a posix usernames, groups, passwords, etc. must 
be stored in distinct locations in a directory ?  I realize this mostly 
applies to the padl pam/nis and the libnsspam-ldapd module specific.

can they be stored in other structures effectively and usefully?  can 
they be stored on a department by department basis, or in any other 
organizational scheme?  (ou=arbitrary1,dc=... having groups and users, 
while ou=arb2,ou=arb3,dc=... also has users and groups?)  if a scheme 
like the above is used, will all users and groups be available on a 
system?  must they be free of naming conflicts, or will 
group=users,ou=arbitrary1,... be different from 
group=users,ou=arb2,ou=arb3,... ?  if they're different, how would this 
be indicated by the systems?