There are four modifiers on a Mac keyboard: command, option, control, and shift. (Fn isn't a real modifier, but it likes to hang out with them on laptop keyboards.)
Option is also sometimes labeled "alt".
Command usually has a four-leaf-clover symbol on it, and sometimes also has an Apple logo on it. You might also hear it called "open-Apple" by people who remember the Apple II, which had open-Apple and closed-Apple keys which mapped to the joystick buttons.
All four of these modifiers have been on all of Apple's keyboards for over 20 years. (Control, the newest one on the scene, appeared on the Apple Extended Keyboard in 1987.)
If the key is labelled alt, call it alt, if it wants to be called steve, then have the documentation refer to it as steve.
It's a keyboard. It shouldn't be this complex.
I get that they want to be all zen and remove unnecessary stuff but some of this stuff is necessary. Not good for users.