

Here we have a soon-to-be-church with the trappings of a soon-to-be-business:


That was on the church-to-be. I've seen hundreds of abandoned buildings with what I assume are squatters' codes: I'm guessing the X and "R.O." stands for "roof open." Does anyone know more about these codes? Are they painted by would-be squatters or by property owners? Or maybe by the fire department?
Note that the next storefront is simultaneously a storefront church and a furniture store. (Why choose just one?) The pastor's name is also Joe. On this particular block, of the 21 storefronts that showed signs of past or present use, six and a half were storefront churches.


Crown Heights, Brooklyn
That square w/X I believe was painted by FDNY. It means DO NOT ENTER - look from the outside only. http://sageauthoring.com/fdny/construction/vacant.pdf
That square w/X I believe was painted by FDNY. It means DO NOT ENTER - look from the outside only. http://sageauthoring.com/fdny/construction/vacant.pdf
Per Dennis's link
If a roof has been previously opened or burned away, to the degree that the need for future vertical ventilation appears minimal, the letters "R.O." (roof open) can be made over the building condition marking.
squatters usually identify their buildings with :
http://www.squat.net/ (the circled N)
r.o. marking is by the fire dept. the marking is solely for the f.d. when there is a fire in that bldg. r.o. means roof open. one line in the box mean enter bldg with exteme caution. an "x" means you can only enter for a known life rescue. these markings were started because of the many arson fires in the 70's and the various booby traps that were set for and killed many firemen.
the x inside the square means the roof/floor has caved in