HP releases the HPUX patch twice a year. Few break-fix patches releases as on need basis. Here are naming conventions being followed by HP.

HP releases OS patches for HPUX every 6 months i.e. twice a year. For smaller HPUX patch which are releases as on need basis, HP follows below naming conventions

Patch name format is PHxx_yyyy

Where,

xx = area of patch
CO: General HPUX commands
KL: Kernel patches
NE: Network-specific patch
SS: all other subsystem patches

yyyy = unique number

From patch name, you will be able to guess area of its impact so that you can plan your activities accordingly. If the patch requires a reboot or not can be determined while downloading the patch from the HP portal itself or even by running swinstall command with -p (preview) argument.

HP patches are available on http://software.hp.com/ which will redirect you to HP software depot home. HP passport login required to download patches or software from software depots.