Unexplained parameter in url from confluence cloud

Hi there,
sometimes our logs show responses where we get the following url parameter back from Atlassian:
i.e. a call to an url containing:

Our app is based on Atlassian Connect Express. Is there any documentation or information what xdm_deprecated_addon_key_do_not_use means? And how we can avoid getting this warning?

@marc That url parameter is for internal use only, and could change/be removed at any time.
It’s not related to the framework you use, or your app specifically.
We used the name as a warning to all apps not to accidentally depend on it.