MI        This condition is triggered when your newly requested name is denied, whether it was your first request to set the name or a request to change it.

There are limitations to the name, covered under the Set Name action. Some limitations such as length can only be enforced by the server, for reasons described under Set Name.

You can use the Deny reason (for on […] denied) expression to get the reason it was denied. The reason may be reset to empty after the event finishes.

The denied client name is not readable, but there should be no reason to be attempting to set your name to more than one thing at once.