Actually, when (not 'if') there is an ambiguously worded SOP, it is clearly by intent. TSA management wants ambiguity (and secrecy).

If you do penetrate TSA's SSI veil of secrecy, you will (by design) find ambiguously-worded, open to interpretation regs and SOP that essentially allow anything and everything a TSO wants to do.

TSA does not want clear, concise procedure manuals.

Question for those who travel abroad: how often do you see 'Kettles' at foreign checkpoints? How are they handled? Do you see and hear the proliferation of signs, recordings, barkings (sounds like the monkey house at the zoo at feeding time) that proliferate at US checkpoints (all paid for by taxpayer dollars)? Do you suppose there are foreign equivalents of out-of-date, ambiguous, worthless security websites? Do you see hordes of security folks standing around with no apparent purpose (non-US airports usually seem to have less than half the folks the US does at any given checkpoint, yet they seem to move far more efficiently). Do you suppose foreign security SOP's are as opaque as TSA's?