Sorry Mike Georgiansilver, try Googling "polari", and you will find more than you want to know about naffs acronymical origin, which goes back many years before Norman Stanley Fletcher (1973).

It may be coincidence, but shortly before the first Porridge scripts, Norris McWhirter had founded the unfortunately named right-wing group National Association for Freedom, which was hastily changed to the Freedom Association when (I assume)someone pointed out that the acronym Naff was already taken.

In Porridge "naff" was used as a clean swearword, but not in the polari sense of bad as in this thread.

nick