!!! Overview
[{$pagename}] ([azp]) is an [id_token] [parameter] which represents the [Authorized party] the party to which the [id_token] was issued. 

If [{$pagename}] is present, it [MUST] contain the [OAuth 2.0] [Client_id] of this party. This [Claim] is only needed when the [id_token] has a single [audience|aud] value and that [audience|aud] is different than the [authorized] party. 

[{$pagename}] [MAY] be included even when the [{$pagename}] is the same as the sole [audience|aud]. 

[{$pagename}] value is a [case-sensitive] [string] containing a [String] or [URI] value.

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]