An expression based on the usage environment of a Link typically including predicates that test the current user's membership in a group or possession of a user role that when evaluated truthfully enables an applicable value for a Link property. For example, User_* indicates that the link property setting applies to all users while User.name = joe indicates the rule applies only to a specific user named joe.
Optionallow
A link property that defines a value range that the evaluated value of the row estimate measure must fall within in order to allow submissions of a request for the link.