This call queries the external directory service to obtain the subject_identifier as a string from the human-readable subject_name

Return value
	type	description
	string	the subject_identifier obtained from the external directory service
Parameters
name	type	description
session_id	session	valid session reference
subject_name	string	The human-readable subject_name, such as a username or a groupname
Errors
name	arguments	description

• Message has only a synchronous version
• This is a custom message