The include and exclude filters apply to both the left and right location(s).
This applies to all sync variants (Two-way, Mirror, Update).
Note that filter definitions are always relative to the root of the left and the right location,
and thus are never absolute (e.g including a drive designation)
> Also, I'm curious, why do you think keeping versioning files in one of
> left or right location(s) is akin to being a "pathological approach"?
Particularly if you are using a Mirror or Update sync in a multi-user environment, both the target (normally: right) location and the versioning location require to explicitly block write access to those locations for all "normal" users other than the user under which the FFS sync is run. Otherwise "normal" users might, intentionally or unintentionally, delete or make changes to the files in the target and versioning location.
(If you are smart, you even do the same in a single user environment.)
Next to that, your source (left) location contains your "most recent" files; the versioning location contains previous versions (if any), and are obviously not most recent,
Both of the above is why having your versioning location inside your source (left) location seems "pathological".
Having it
inside your target (right) location seems illogical, as that location contains "backups" of the most recent version of the source location (at the time the sync was run).
If you need a previous version, you visit the versioning location. As the most recent previous version of a file is stored there under the same name as the file in the source and target location, it is best to create the biggest awareness that it concerns a previous version and not the most recent version. Using a separate location helps in creating that awareness
> Also are you implying that keeping versioning on both left and right locations wouldn't be "pathological"?
I did not make a statement to that extent or with that intent (nor to the opposite ...).
Having versioning locations on both the left
and right sync location is not supported by FFS, and in my view that makes a lot of sense.
> ... Is it possible to setup versioning so that it only keeps, say, the six most recent files of versioned files?
No that is (in my view unfortunately) presently not an option.
It is either just the last previous version or all previous versions.
There has been an
extensive discussion in this forum on that topic some time ago