My digital forensic analysis (levels adjustment):

I'm not certain about the last letters, but I'm sure there is a small צ (between the ח and first צ) and a descender under the first letter. The descender could have resulted from having been folded against the first letter, but there is no evidence of other letters transferring. 

 **ץ**אא ח***צ***צ’'צ בור**יץ**


Maybe the חצ"צ stands for :
**ח**ילי **צ**בא **צ**'כוסלובקיה
(The Soldiers of the Army of Czechoslovakia or a Soldier in the Army of Czechoslovakia)