Where to put "metadata" files not visible to user?

My company uses OwnCloud to sync data from partner companies. In the files back-end, a script triggers every several minutes to scan the uploaded files and inject the contents into a database.

The problem is, the format of the data our partners upload are varied. We decided rather than performing an auto-detect, we'll just put a "config.yaml" file somewhere within the user's OwnCloud directory. That is, a "metadata" file that describes the partners' data format.

This begat another problem: How do we ensure the file to be protected from inadvertent erasure and/or editing.

I had this idea:

  • First time config.yaml is found under <userdir>/files, it gets copied into <userdir>.
    • If a new config.yaml file is detected (based on timestamp), the new file overwrites the old file.
  • When the file is missing and a copy exists in <userdir>, the copy gets written back to <userdir>/files and an occ sync performed (to push back the config.yaml file to the partner's client).

Now my question: Is placing an additional file in <userdir> safe? That is, will OwnCloud Server leave the file alone and not delete/overwrite it?