The usernames given on signup are not sanity checked.
They allow "two-letter" names, and also way too long names like:
{F2012, size=full}
Login by mail, works from registry side.
However those names cause issues on starmadedock.net (as the forum does not seem to accept "too short" or "too long"names.
Also the game has issues authenticating when things like @ get into the name.