Old Jun 14, 18, 2:34 pm
  #2  
NHFL9
 
Join Date: Jun 2002
Location: NYC
Posts: 2,762
You may want to consider opening a FlyingBlue account or something like that and having them add that number to the reservations you don't want to earn DL miles on. As long as your known traveler number stays in the record you should keep PreCheck. I think this is totally fine, you can choose what program you want to earn miles in for a given flight.
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