Name linking follows Twitter rules... as in, we use the same matching code as Twitter for their matching, and their usernames do not allow anything other than alphabet, numerics and a very small selection of other characters (which doesn't include &).
It was also how some people avoided being @mentioned because they put non-printing unicode in their username (though unfortunately abuse of that has meant I've now disallowed that).
Name linking follows Twitter rules... as in, we use the same matching code as Twitter for their matching, and their usernames do not allow anything other than alphabet, numerics and a very small selection of other characters (which doesn't include &).
It was also how some people avoided being @mentioned because they put non-printing unicode in their username (though unfortunately abuse of that has meant I've now disallowed that).