EXtensible Access Control Markup Language

Overview
The EXtensible Access Control Markup Language (XACML) is a standard that defines a declarative access control policy language implemented in XML and a processing model describing how to evaluate access requests according to the rules defined in the policies.

As a published standard specification, one of the goals of XACML is to promote common terminology and interoperability between access control implementations by multiple vendors. XACML is primarily an Attribute Based Access Control system (ABAC), where attributes (bits of data) associated with a user or action or resource are inputs into the decision of whether a given user may access a given resource in a particular way. Role-based access control (RBAC) can also be implemented in XACML as a specialization of ABAC.