<patch patch record>

── $- ──<patch>────────────────────────────────────────────────────────┤

$- records are used to patch a patch. A patch patch record is treated as a regular record in that it must have a sequence number and can delete a record in a previous patch at that sequence number; however, it is not included in the PATCH file. The records let the original source filter through with the original patch number (if any) without changing an established patch or replacing the source and losing the patch number.