I am locked out of nfpa for a few minutes so I cannot check 2010 and 2013, but from 1999 appendix
The NFPA reference isn’t in the Life Safety Code, though — it’s in NFPA 13, Installation of Sprinkler Systems. I’ll use the 1999 edition of NFPA 13 because it’s what The Joint Commission currently recognizes.
Under that edition, look at annex note A-5-6.6:
The 18-inch dimension is not intended to limit the height of shelving on a wall or shelving against a wall in accordance with 5-6.6. Where shelving is installed on a wall and is not directly below sprinklers, the shelves, including storage thereon, can extend above the level of a plane located 18 inches below ceiling sprinkler deflectors. Shelving, and any storage thereon, directly below the sprinklers cannot extend above a plane located 18 inches below the ceiling sprinkler deflectors.