While I agree with the literal truth that "(t)here is no such thing as a document that totally has no unambiguity in it," (emphasis mine) I think that it it possible to have documents that are very clear, with ambiguity reduced almost to the vanishing point. Check out the FAR for an example of a government-produced, aviation related document that is very clear on what the rules are for operating aircraft in the nation's airspace.

It would be ridiculous for a pilot to say, "The visibility requirements for VFR in Class B,C or D airspace are poorly defined," or "It's unclear what the minimum altitude over a city is." Those things are spelled out quite clearly and unambiguously. And failure to comply with the requirements can cause a pilot to lose his privileges.

If the FAR can be laid out in a clear, unambiguous fashion I would think that things such as the list of acceptable ID at a TSA checkpoint could also be clearly and unambiguously stated. And, in fact, the acceptable ID list is clear and unambiguous. And yet, we see almost weekly posting about a TDC who refused a Nexis card.

If there is an issue with an ambiguously worded SOP, then there is a problem with TSA management. They have the responsibility to produce clear procedure manuals. If there is an issue with TSOs not being able to comprehend the SOP there is a problem with workforce. I suspect both problems are afoot at TSA.