A number of maps have been added to the map vault for the purpose of allowing people to play unraked matches, while gaining rank nonetheless.
The majority of them have "Voodoo" in the title (I blame Voodoo for this, those germans are always causing trouble ;) and the most commonly played are variations on Battle of Thermopylae.
You will even often see people who host these maps naming their lobby things like "noobs only, no air, Ranked".
I have many times been kicked from these lobbies merely for asking that air be disabled, if the map disabled it, or requesting that nukes and t3 arty be disabled, if the map disables it. Many hosts have even admitted the reason for refusing to disable air/naval/etc when the map disables it, is that they want a ranked match, or they need the rank too badly to disable it.
The rating system is already inaccurate and unreliable enough, except when the vast majority of someone's rank is gained through matchmaking, and even then its not terribly reliable. This just makes it a joke when people can play with air, naval, t3 arty, nukes, etc all disabled in the same match and gain matches played and incease their rating via matches that are obviously meant to be unrated, yet this mapmaking glitch/exploit permits these matches to count as ranked anyway.
A couple of the maps that seem to exploit this glitch are:
Voodoo Thermo Spezial v1
Voodoo Thermo v3
These two maps alone have had over 7000 downloads and near 5000 plays, thats a lot of added inaccuracy in an already inaccurate system that is too heavily relied on when determining who can join a lobby.
Hopefully some map pros can add to this list of maps designed to exploit this glitch.