This is a list that lists (heh) games available in people's Steam libraries but that are not listed on the profile. Why are they not listed, and some never were? Ask Valve. Some of the listed game are no longer sold on Steam, but that would not be the reason they are not listed.
¹The "Who Wants To Be A Millionaire? Special Editions" listed above is not shown. It never was. There is now (since October 2013) a separate regional version for the US market that is listed. That one is 232670. The still unlisted one is 206740.
If/when any are fixed, I will cross them off, but for historical purposes will remain listed.