Fob

I studied a new English word! Ya mama!

The word is "fob". Definition in Merriam-Webster:

1 : WATCH POCKET
2 : a short strap, ribbon, or chain attached especially to a pocket watch
3 : an ornament attached to a fob chain

I learnt it from UK's new airport security measures. It allows "keys (but no electrical key fobs)". Among other things it means that you can't take you disk-on-key a.k.a USB flash drive and probably any other USB gadget into the plane cabin.

Several strange things:

1. In that sense, fob should have meant "key holder", but it doesn't - see above.
2. The first two native English speakers that i asked about this whole thing didn't know what am i talking about. They heard the word "fob" from me for the first time. (They are both Americans, however.)
3. The 1947 edition of the Oxford Pocket Dictionary marks this word as "historical", but the latest Merriam-Webster does not.
4. Blogger's spelling checker recognizes "fob", but not "fobs".
5. Most importantly: Are these security regulations written for Average Joe Tourist? Or are they intentionally obscure?