The Union Platform (tm)

Implement a system where a client attribute can be defined as "unique," meaning that the attribute value must be unique among the clients that define an attribute by the same name.

Use case:

A client with no user account in a chat room chooses a screen name, such as "Tom". The chat application uses a "unique attribute" to guarantee that no other client can use the screen name "Tom" for the duration of the chat session.

Implementation:

• The u3 message should specify that an attribute is unique by setting bit 4 of the attrOptions parameter.
• If a client sets an attribute to a duplicate value, that client receives a u8 with the status ILLEGAL_DUPLICATE_VALUE