"Special neckerchiefs, the same size as the official ones, may be authorized by local councils. Such neckerchiefs may include identification of the chartered organization. The standard designed neckerchief may be personalized with troop number, city, and state. By troop approval, an Eagle Scout may wear an Eagle Scout neckerchief."
BSA, Guide to Awards and Insignia, "Special Regulations," "The Neckerchief."
This has been the regulation forever and ignored systematically just as long. I don;t know of a single unit that got Council OK for a non-official neckerchief (nor does either council where I scout) or bothered about whether their special neckerchiefs were "the same size as the official ones." I have been in four troops since 1983 and they each had a special neckerchief without council consent that was not the same size as the official ones. The language should be eliminated.