I recently picked up a 2016 Macbook Pro (with Touch Bar). I use an external keyboard. There used to be a setting in the keyboard system preferences that "Use all F1, F2, etc. keys as standard function keys". That is no longer an option. Is there a way to get that back?
At least in Sierra 10.12.3, the Keyboard panel of System Preferences has a check box for that which says:
Use F1, F2, etc. keys as standard function keys on external keyboards
When this option is selected, press the Fn key to use the special features printed on each key
This may not apply to everyone, but in my case, I am using a Logitech Keyboard (K750). The Logitech control panel has an override to use the F-keys as standard function keys.
You can install Karabiner-Elements.
In karabiner-elements Preferences, in the Function Keys tab, there is an option at the bottom, "Use all F-keys as standard function keys"