Answer:
   
   Those abbreviation are shorthand for common Hebrew phrases. Here are
   some of the most common ones:
   
   A"H 
          (Alav (Male), Aleha (Female) Hashalom)
          
          + For any deceased Jew.
          + Translation: Peace Be Upon Him/Her
          + Sometimes written as PBUH, generally by Muslims.
            
   Admo"r 
          (Adonainu, Morainu, VeRabbeinu)
          
          + Translation: Our Master, Our Teacher, and Our Rebbe
          + Honorific title given to scholarly leaders of a Jewish
            community, "R' Ploni Almoni, SHLITA, Admor of Chelm.")
          + This is usually a specifically Hassidic term.
            
   AMUSh 
          (Ad Maia Veesrim Shana)
          
          + Translation: [He/She should live] for 120 years
          + Used for salutations in correspondence: "Dear Ploni AMU"Sh"
            
   B"H 
          (Baruch Hashem)
          
          + Translation: Blessed be G-d (occasionally) (B'Ezras/Ezer
            Hashem)
          + Translation: With G-d's help (i.e. at top of papers,
            sometimes with an ayin following the beis)
            
   B"N 
          (B'li Neder)
          
          + Translation: Without taking a vow
          + Used after a promise, since failure to fulfill a promise is a
            serious violation of Jewish law. For example, "I'll check
            that reference tomorrow, B"N." (i.e., if I forget, I don't
            want to be liable under Jewish law).
            
   BLA"H 
          (B'li Ayin Hara) or (K'ain Ayin Hara)
          
          + Translation: "without the 'evil eye'"
          + Meaning: "I'm saying this without hubris"
          + Often pronounced Kanaina horo (Yiddish)
            
   BS"D 
          (B'siyata d'shmaya) (Aramaic)
          
          + Translation: With the help of heaven (common)
            
   HY"D 
          (Hashem Yikom Damo[am])
          
          + For martyred Jews.
          + Translation: Hashem will avenge his[their] Blood
            
   IY"H, IYH 
          (Im Yirtzeh Hashem)
          
          + Translation: If it be G-d's will (very common)
          + Used for referring to future actions: "I'll see you tomorrow
            IY"H."
            
   N"E 
          (Nishmaso(male)/Nishmasa(Female) b'Eden)
          
          + Translation: His/Her soul should be in Eden/paradise
            
   R'
          (Rabbi)
          
   ShLIT"A 
          (SHe'yikhye Lirot Yamim Tovim ve'Arukim)
          
          + Used for living prominent Jewish scholars.
          + Translation: That he/she should live to see good and full
            days (long life)
            
   YM"SH,Y'Sh,Y"ShU 
          (Yemach Shmo Vezichro)
          
          + For deceased enemies of the Jewish people
          + Translation: May his name be wiped out (YH"SH, Y'Sh); May his
            name and memory be wiped out (Y'Shu)
            
   Z"L 
          (Zichrono Livrocho)
          
          + For deceased prominent Jewish scholars.
          + Translation: Of Blessed Memory
          + Sometimes written as OBM
            
   ZT"L 
          (Zecher Tzadik Livrocho)
          
          + For deceased prominent Jewish scholars.
          + Translation: The Memory of the Righteous is a Blessing