SMS Message Formatting

Formatting like bold text or italics, in general no - unless some particular SMS providers use a proprietary format for doing this (I'm not aware of any).

Standard SMSes are encoded using the GSM 03.38 7-bit alphabet which does include CR and LF (and FF) characters, but how these are rendered is up to the receiving end. Out of the two implementations I have to hand, both just ignore CR or LF (but one of them renders a line break if the message includes two consecutive spaces).