!!! Overview
[{$pagename}] or a user [attribute] is an [AttributeType] with an [Attribute Usage Flags] of "userApplications".  

User [attributes] are used for actually storing information in the directory, as opposed to [OperationalAttribute] which are used for storing state information used for internal server processing.

Whenever a [SearchRequest] does not contain any specific attributes to be returned, then all [user attributes] in matching entries will be returned.  

An explicit value of "{{*}}" (the asterisk) may also be included to explicitly include all user attributes.!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]