A PAL base type. Most PAL entities derive from this type. A PAL entity consists of an identifier along with an optional name element. A PAL rule data type. PAL Rule is-a palBaseType including a choice between a self-contained code-snippet which represents the underlying rule or a reference (URI Reference) to the rule itself. A PAL Presence Aspect data type. PAL Presence Aspect is-a palBaseType including a Presence Aspect value data type, and a URI reference to the rule which may be resolved for the associated PAL Presence Aspect. A PAL Presence Trigger data type. PAL Presence Trigger is-a palBaseType including a URI reference to the associated pre-defined action and the underlying Presence Trigger rule for the underlying PAL Presence Aspect being monitored. A PAL Rule-Set data type. PAL rule-set consists of 1 or more pal rules with a mandatory rule-set identifier attribute. A PAL Aspects data type. Aspects consists of 1 or more pal aspects with an optional aspects identifier attribute. A PAL Triggers data type. Triggers consist of 1 or more pal triggers with an optional triggers identifier attribute. PAL Profile type. Note that items from other namespace may include policy type definitions. PAL Profile document structure.