setting up a logitech g510 G keys.
download logetech gaming software and install.
once installed open software and click on the g keys on the left or right click to open edit part,
on the left you will see commands +. click on the plus sign to start the edits for keys.
the command edit screen opens and you want to  click on text block, a new window opens and now you see  name and enter text.
so now you name the key ie: no running and then in the text block type no running. or what ever you want to say, then press ok
once you press ok you will see in the left side your key bind just left click on it and drag it to the first G-key you want.
now repeat the process for any other binds you want to make. once done you will want to test your binds , just get into a game
and then hit you chat key J and press the G-key you want for your message to appear in game chat.

ADDED A WORD DOC IN ZIP TO HELP WITH VISUALS OF SETTING UP A G-510 KEY BIND

Yay thank you. I'm sure this method also works for the COD games.

I guess this works for any other Logitech device with the -G keys...  Other keyboard models,  headphones,  miceseses.

Also, when setting this up, "check"  USE DELAYS BETWEEN CHARACTERS.  25 ms seemed to work.
                                          "check"  USE UNICODE PLAYBACK.

I had some issues until I did this.

I'll try it on my g15