Reserving licenses is an RLM feature and is documented in the RLM User Guide (see “The ISV Options File” section).
You use the RESERVE keyword in the ISV options file (solidangle.opt) to reserve licenses for specific users, machine names, or IP addresses.
For example, this reserves 2 licenses for machines with the specified IP addresses:
INTERNET_GROUP renderfarm 192.168.221.1 192.168.223.1 RESERVE 2 arnold group renderfarm
This reserves five licenses for named users:
GROUP myusergroup steve stephen steven stevie stevo RESERVE 5 arnold group myusergroup