<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by bonzaiflyer:
As noted above, it's "X" for domestic. However, for Mexico, Caribbean and (I think) 3 class domestic upgrades to 'business' class, it is "R".
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that is correct. and note that X and R should not appear at all (even as X0 or R0) until 100hrs before flight time since they don't really exist until then.