Disable Steam notifications in-game only

Solution 1:

If you go in-game and do shift+tab, you get that odd overlay menu. in the friends pop-out there is your name, and a settings symbol next to it.

click it and you get a "friends light settings" menu

go to the Notification tab and uncheck everything

Solution 2:

It would appear that there is no way of disabling notifications in-game only, while still keeping the steam community enabled in-game.

Either notifications need to be turned off globally (View -> Settings -> Friends -> Uncheck all the "Display a Notification" check boxes), or the steam community needs to be disabled in-game in order to prevent me from receiving notifications in-game.