Which remotes support polling?

[H4v0k]

Is there a list anywhere of which remotes support polling?
I checked the overview page on the main site but it doesn't seem to list them there.

I'm setting up a server that will act as the source of files and was wondering whether to set it up as sftp/ftp/webdav/s3 compatible/etc. And figured it'd probably be best to set it up as a remote that supported polling (if available) but can't find any info on which remotes support it.

Thanks

[kapitainsky]

Looking at backends source code it is implemented for:

OneDrive
Google Drive
Dropbox
Box

I also used grep:)

In backend directory:

grep -R "ChangeNotify" *