UnitedFlyer is right on...

I looked it up in Apollo - here is the description....

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* BP5A - BEST AIRLINE PRIORITY SUCH AS -MISCONNECTS- *
* ----- DENIED BOARDINGS/DISSERVICED ETC. *
* THIS COULD INCLUDE DISSERVICED BP1B/BP3/BP4 *
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* BP5B - ALL OTHER REVENUE STANDBYS-ALL ECONOMY TICKETS*
* INCLUDING NF/NC. NOTE: WILL SORT BY MILEAGE *
* PLUS STATUS FOLLOWED BY BOOKING CLASS CODE. *
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