Lineholders only. It's what is called "Posted Sequences" for other pilots to pick up. Weekday turns and 2-days are easiest to dump, but even the 2-days are such garbage anymore it's not a sure gig'.

The "good old days" would have you dropping a 2 leg/2-day with a late afternoon/evening departure to some place like Cali or Barbados followed by one leg home and done by noon. One could dump those 1 day after bids close. Those trips disappeared. Now, if you depart later than 10am on the first day, count on returning past 8pm on the second for close to the same pay.

Reserve days can't be dropped. Whatever you're awarded, you eat. I've never heard of anyone trading Reserve Days either.