Abbrvtn "S.A.W." in Islamic writing.

Just looking at some writings on Islamic belief and I notice that after most usage of the name of Mohommed or other prophets or spiritual types there is an abbreviation. Usuall this is S.A.W. but sometimes it’s S.W.T., R.T.T or something else.
Occasionally there is no abbreviation.

The question is, what do they mean?

Example

http://students.washington.edu/rameez/islam/articles/proofs.htm

After saying or writing the name of the Prophet, it is traditional to give a benediction, usually a version of “Peace Be Upon Him.” When you speak, you say the phrase. When you write, you often use an abreviation. English writers often use PBH, for “Peace Be Upon Him,” SAW (for “Salalaho Alaihi Wa Alehi Wa Sullaam”) is more technically correct, however, though it means pretty much the same thing.

The same benediction can also be used after the name of Jesus, Moses, Gabriel, etc. It can even be used when refering to “ordinary” people whom the speaker or writer has great respect for.

Thanks very much.

Any idea what SWT or RTT might mean? Are they variation of the same theme?