OK. I already purchased the book of NFPA13 from your organization and have all the codes. My question was specific because it lays in a "grey" area. NFPA codes allow for spriklers of ESFR TYCO 9226 pendent k25 to be located under the ceiling by a max. of 45 cm . We have ceilings that are 14.6m high and that is where the conflict is. NFPA allows for 45cm but the UL listings allow for a max distance from ceiling to sprinkle head 35cm !!! that is a conflict as NFPA do not have codes for the 14.6 meter hight of a hanger when measured from finished floor level to ceiling level. I do not think that I will get an answer from your existing codes , that was my reason in trying to contact one of your experts to see if you have something new concerning this subject.I cannot find any information from NFPA concerning the codes for sprinklers for ceiling heights of 14.6 meters. Or , do you know something new ? Thank you for your time and much appreciated .