This attribute corresponds to the -proxyUserid startup parameter. If -proxyUserid is not specified on the command line, this attribute has the Unknown value (?) until it is set.
This attribute is validated during the CONNECT( ) method (for an AppServer and a Web service). If PROXY-USERID is invalid, the CONNECT( ) method fails and the AVM issues an error message.
PROXY-USERID must be a string of up to 512 printable ASCII characters, including the space character.