User-defined vs. system-defined categories

Some categories are user-defined, which means you can add and edit them. Other categories are system-defined, and cannot be edited. The categories which cannot be edited or changed are as follows:

Plant
Job Code
Equipment
Time of Day
Customer
Job Address
Phase Code
Mix Code
Liquid AC
Crew Type

You can add, edit, or delete category items for both user-defined and system-defined categories.