Write splice
The magnetic seam that forms where a new write session meets previously written content on tape.
Tape is written sequentially, and when you append data after a pause the new writing can never be erased perfectly into the old flux pattern. Where the sessions meet there is a discontinuity — a write splice — and the reader has to resynchronise its clock across it, much as it does with every leading preamble. Drives therefore deliberately leave a small gap around the splice.
On linear computer tape such as a tape streamer, a splice appears at every append, and too many splices fragment the tape in their own way. The word also has a literal meaning: the physical splice where two lengths of tape were joined with adhesive, once a routine repair.