How do I filter out games which require my telephone number in order to play them?

[error]

I've just had to request a refund for MWIII right after buying it and don't want to have to go through that process in future. It would be good to simply not see these games advertised to me on Steam. I use a VOIP service and Steam/Activision do not recognise my telephone number.
How do I filter them out or how can I determine before buying that there will be a problem with my telephone number?

[Faedrill]

I didnt know there are games that requiere a telephon number to play them.

I would say stay away from multiplayer games (cant imagine a singleplayer game would ask for it) or ask in the Forum of the game.

[Kargor]

Who was asking for a phone number?

If it's the game itself, you'll have to check individually on the other games in the series. Not a lot of games ask for a phone number, so you should be safe enough. Also, check forums and/or guides; if's probably mentioned.

If the game requires some 3rd party account which requires a phone number, just skip all the games that require this particular account. As an example, if I search for your "MWIII" I end up with an Activision game that says "Requires 3rd-Party Account: Activision Account", so I'm guessing you'll want to avoid these.

[error]

'Who was asking for a phone number?'

Activision (MWIII) via Steam.
I requested a refund from Steam and although they granted it they have deducted over 20% for some reason. (I requested refund right after purchasing the game - as soon as I found that my VOIP number was not recognised by Steam.)
This is an expensive way to discover a game you cannot play and I was hoping to find a way to filter out such games in future. At the very least I need to be able to determine in advance of taxation that the game is unsuitable for those who prefer to use a VOIP service as I and many others do.
So far no luck.