Program numbers are given out in groups of hexadecimal 20000000 (decimal 536870912) according to the following chart:
0 - 1fffffff defined by firstname.lastname@example.org 20000000 - 3fffffff defined by user 40000000 - 5fffffff transient 60000000 - 7fffffff reserved 80000000 - 9fffffff reserved a0000000 - bfffffff reserved c0000000 - dfffffff reserved e0000000 - ffffffff reserved
The first group is a range of numbers administered by email@example.com and should be identical for all sites. The second range is for applications peculiar to a particular site. This range is intended primarily for debugging new programs. When a site develops an application that might be of general interest, that application should be given an assigned number in the first range. Application developers may apply for blocks of RPC program numbers in the first range by sending electronic mail to "firstname.lastname@example.org". The third group is for applications that generate program numbers dynamically. The final groups are reserved for future use, and should not be used.