Introduction to policies and expressions
For many Citrix ADC features, policies control how a feature evaluates data, which ultimately determines what the feature does with the data. A policy uses a logical expression, also called a rule, to evaluate requests, responses, or other data, and applies one or more actions determined by the outcome of the evaluation. Alternatively, a policy can apply a profile, which defines a complex action.
Some Citrix ADC features use default syntax policies, which provide greater capabilities than do the older, classic, policies. If you migrated to a newer release of the Citrix ADC software and have configured classic policies for features that now use default syntax policies, you might have to manually migrate policies to the default syntax.
This document contains the following details: