Category declarations

Declarations of attribute categories provide short names for them and make the categories available for use in attribute declarations. Users typically do not need to declare their own categories since system.alfa declares the four standard attribute categories, as follows:

category subjectCat  = "urn:oasis:names:tc:xacml:1.0:subject-category:access-subject"
category resourceCat = "urn:oasis:names:tc:xacml:3.0:attribute-category:resource"
category actionCat = "urn:oasis:names:tc:xacml:3.0:attribute-category:action"
category environmentCat = "urn:oasis:names:tc:xacml:3.0:attribute-category:environment"