The text is on reverse side of photo taken before 1918 at the village Bolhovets (suburbs of Belgorod, south-west Russia).
I tried so far to find if any language has a letter visually similar to # sigh, but could not find any reference. Also, the top line looks like a date, the notation of number 1 and 9 (assuming last 4 symbols are the year) does not help to identify language either.
