Some of them (like Ascend) has vendor specific ones. Here is the list
from the RFC:
1 User Request
2 Lost Carrier
3 Lost Service
4 Idle Timeout
5 Session Timeout
6 Admin Reset
7 Admin Reboot
8 Port Error
9 NAS Error
10 NAS Request
11 NAS Reboot
12 Port Unneeded
13 Port Preempted
14 Port Suspended
15 Service Unavailable
16 Callback
17 User Error
18 Host Request
-- Dale E. Reed Jr. (daler@iea-software.com)_________________________________________________________________ IEA Software, Inc. | RadiusNT, Emerald, and NT FAQs Internet Solutions for Today | http://www.iea-software.com