syncthing-versioning(7) on Linux
The text 23311ebab75d, as Debian 10 (Buster) shipped it.
Keep automatic backups of deleted files by other nodes Syncthing supports archiving the old version of a file when it is deleted or replaced with a newer version from the cluster. This is called “file versioning” and uses one of the available versioning strategies described below. File versioning is configured per folder, on a per-device basis, and defaults to “no file versioning”, i.e. no old copies of files are kept.