It would be nice that if you could maintain a list of which regional carriers operate for which mainline carriers.
For Example, for NWA, we have MES, FLG, and CPZ.
For the flight previously mentioned, if NWA2936 was inputted, it would be nice for the system to recognize NWA and only display flights from known NWA regional carriers instead of a whole slew of flights that could never be the one a user is looking for.
The problem with this is that many regionals operate for two or more carriers. Examples:
Skywest operates for Northwest, Delta, and Midwest.
Expressjet operates for Delta and Continental in addition to their own branded flights.
Mesa operates for Delta, US Airways, and United and also under the gojet name
Also, what about the major airlines that code share on another major airline? Example: