I'm having trouble finding any information on the orange X's next to my gamertag when i customize a match. I'm pretty sure it means that however you play in the game, it doesn't count towards my accolade/skull emblem.

i noticed that it appears whenever i change the game from its original setup. I also noticed that it appears when i have a guest playing with me. Is this the case? And also does it not benefit when I play local matches instead of online matches?