Originally Posted by KVS
Generally, it's the change in routing that triggers the re-issue. Stickers can be used for simple date changes, or changes from an OPEN segment to a specific one.
It also depends on the airline -- for example BA no longer allows stickers (partly for security reasons) and requires that tickets are to be re-issued.
I saw BA sticker AA-issued award tickets not even two weeks ago. Did something change more recently, or is that distinct for some other reason?