There are a bunch of MS multimedia ones that have a FN lock key. You need to push it first (and an LED comes on) to get normal F key functions. Otherwise you get the additional printed function on the key.
(they also tend to move the 6 keys about with pgUp/Dn, Home/End, Ins/Del on them, lose a key and Make Del oversized which is a right PITA if you are used to using those keys for editing).
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