replying inconvenience after displayed users' display name

I'm glad that in mobile version, usernames are replaced by display names. It's convenient for us to recognize the repliers as at most times we only know their display names rather than usernames.
However, for the same reason , it has become difficult for us to reply the repliers in the way of typing @+username
so i have a idea is, to add a username after users display name within a small tag if they're difference, for example, my username is doggie, and my display name is 'Doggie', so the code could be:
Doggie<small>(doggie)</small> [content of a response].
the layout will be:


ps. my username in PCTP was changed to 'alreadytaken' strangely so that i cant login PCTP! My username in plurk.com is 'doggie', please help me to solve this, thanks so much!