Using the Letter (ص)
Question :
Some people, when they write, use the letter )ص( or the letters )صلعم( as symbols instead of fully writing. Is this acceptable?
Answer:
It is wrong to use the symbols you mentioned, even tho in the recent past, many authors have begun to do so. What is correct is to fully write "صلى الله عليه وسلم", so that thevreader reads it, and not just the symbol. This is to make sure that the reader gets the reward of sending prayers and peace on the Prophet, ﷺ rewards that he would not get were he simply to read the letter "ص"
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 8 Page 215