One of the rules for the UA RTW is no backtracking. I understand this to mean that you can't go backwards. But what if the only *A route to your next destination requires a connection through a city you have already transited? Are you just out of luck? For example, if you want to go from DC to Prague, the SA website says take Lufthansa from IAD-FRA-PRA. But if you want to go from Prague to Athens, SA says take Lufthansa PRA-FRA-ATH. My question is, does the double connection through FRA violate the backtracking rules?