Field Rules Management

Field rules define the behavior and constraints on fields. Available field rules are listed as follows:

Field Rule	Description	Incompatible Rule	Apply to Field Type
Allowed Values	Defines a list of allowed values for the field. The field contains a list of options.	None	String, User, Integer and Double
Copy	Specifies a value to be copied into the current field.	None	All
Default	Defines a default value for the field.	None	All
Empty	Defines the field as empty. The field value is cleared.	Required, Readonly and Server default	All
Readonly	Defines the field as read-only. The field can not be modified.	Empty and Server default	All
Required	Defines the field as a required field. The field can not be empty.	Empty	All
Server default	Specifies a server component that will provide the field value.	Empty and Readonly	User, DateTime and Date
When	Specifies one or more rules to apply to the current field when another field has a specific value.	None	String, User, PlainText, Integer, Double, DateTime and Date
When not	Specifies one or more rules to apply to the current field when another field hasn't a specific value.	None	String, User, PlainText, Integer, Double, DateTime and Date

The following fields can not be set rules for: ID, Project, Issue Type, Rev, Changed by, Changed Date, Commented Date, Commented by, Attached File Count, Created by, Create Date and State.
"When" and "When not" rules can not be set for "When" and "When not" conditions.
When" and "When not" rules can not be set for fields in transitions of the workflow.
Rules in different transitions will not affect each other. For example, the incompatible rules Readonly and Empty can be used in different transitions.