bin - owner of all binary files - do not delete - system user
lp - printing owner - do not delete - system user
nuucp - UNIX--to-UNIX copy program user - do not delete - system user
smbnull - used by Samba - delete and remove Samba package if you are not using it
mysql - MySQL user - delete mysql package and the user if you do not use MySQL
tftp - user of the tftp - not sure if it is system user
In general don`t delete system users even if you do not use the applications. Deleting those accounts adds 0 security and may break updates, system etc.
Btw - 11.11 is old - almost obsolete. If you are building system now better start with newer version and if you are trying to secure old system better re-thing upgrading before deleting users
HP-UX 11i support matrix:
http://h20338.www2.hp.com/hpux11i/do...uxservermatrix
You may want to take a look at:
https://h20392.www2.hp.com/portal/sw...Number=B6849AA
http://h71028.www7.hp.com/enterprise...-overview.html
http://www.amazon.com/HP-UX-11i-Secu.../dp/0130330620