'SS', 'Ss', 's/s' and so on can have many meanings.
SS -- 'steam ship' -- as in 'SS Great Britain'
SS -- 'Schutzstaffel' -- the armed wing of the Nazi party in 1930s and 1940s Germany
s/s -- 'signs and symptoms' -- a medical term
Ss -- 'saints'
SS -- 'secret service'
The abbreviation for "southern" is usually "S." or "Sth." in written text.
You place begin as a text abbreviation for beginning
The abbreviation "pH" stands for "potential of hydrogen" in text.
it means "super, kk" (kk means ok)
In text messages, the abbreviation "nk" typically means "no kidding."
TOU
'LYMY' is the abbreviation for 'Love You, Miss You' in text.
"BYF" is an abbreviation for "Bring Your Friends."
Abbreviation of 'what is up'
database
The abbreviation for south is S.
I would presume that the abbreviation for book would just simply be bk, as it is a way of both shortening the word, and removing the double vowel, so that it is easier to text.