Comment by jws

Just a historical note: Patching used to be much more common. Back in the Vax VMS days the image file format (executables, not pictures) had a section for patches.

From the ANALYZE/IMAGE command…

Patch information --- Indicates whether the image has been patched (changed without having been recompiled or reassembled and relinked). If a patch is present, the actual patch code can be displayed. (VAX and Alpha only.)