But in the case of the exam question being referred to in this thread, that "the shop you received the cylinder from put a sticker on it" for your benefit is exactly what the exam question is assuming. So, for the purpose of providing the answer PADI believes is correct, it does matter.Whether the shop you received the cylinder from put a sticker on it or not does not really matter...Typically when one picks up a NITROX cylinder one has either requested in advance a certain mix (even if that was a standard mix of 32% or 36%) or the shop mentions the O2% sometime between handing over the cylinder and the client walking off with it.
-Z
As I said in a previous post, I would not compare my analysis with anything on a sticker that I may find on my tank indicating someone previously analyzed it; rather, I would ask myself whether my analysis reveals an O2 percentage of approximately what I expected, and if it is, I would fill out my own tank sticker.