After reading both the comphrehensive rules and the MTGCommander.net rules, it appears that the two contradict each other on whether or not effects that refer to cards from outside the game continue to function?
In particular, the Comprehensive Rules state that:
903.1. In the Commander variant, each deck is led by a legendary creature designated as that deck’s commander. The Commander variant was created and popularized by fans; an independent rules committee maintains additional resources at MTGCommander.net. The Commander variant uses all the normal rules for a Magic game, with the following additions.
903.11: If a player is allowed to bring a card from outside the game into a Commander game, that player can’t bring a card into the game this way if it has the same name as a card that player had in their starting deck, if it has the same name as a card that the player owns in the current game, or if any color in its color identity isn’t in the color identity of the player’s commander.
This makes it sound like so long as a card from outside the game would obey deck construction rules, it's legal to bring it in. At the same time, MTGCommander.net rule 10 is pretty explicitly against that:
10: Parts of abilities which bring other traditional card(s) you own from outside the game into the game (such as Living Wish; Spawnsire of Ulamog; Karn, the Great Creator; Wish) do not function in Commander.
Since CR 903.1 imports MTGC 10 into the game, how is the contradiction with CR 903.11 handled?
I am no expert, but from my reading it seems like 903.11 is a rule for play groups that ARE allowing cards to be brought in from outside of the game considering the leading phrase "if a player is allowed". It is also possible that 903.11 was written first or was written before some amendment to 10 (if one occurred)