RT Etiquette

Dear Cybersorter,
What is the difference between symbols for retweeting, such as “?”, instead of the acronym “RT” in Tweets
Can I safely use the symbol for retweeting that is inserted by my Twitter application regardless of what application my followers use?
Or would using the acronym “RT” be safer and better etiquette. Does everyone understand these symbols or do they automatically convert to “RT” for anyone using an application that doesn’t support these kind of symbols?
H.O

Dear H.O,
The short answer is yes, you can safely use the symbol for RTing regardless of the application your followers use.
According to Twitter supremo Damien Mulley of Mulley Communications, “Retweeting was invented by the users, not Twitter and Twitter then made this function official.”
The old method of retweeting took up precious characters out of the 140 allowed per tweet so Twitter invented an RT button that used your avatar pic to notify a retweet.
Mulley also notes that though the new method of RTing keeps all context, “users have noted an old-style manual RT can get more attention as it’s your icon and username that shows up, so people will look at a username theyre familiar with.”