What is the purpose of "ONVIF Events" as a filter in the BI app's alerts list?

[Tygunn]

I activated ONVIF on a camera for the first time yesterday; it works great so far. I see the camera reported events marked as "external" triggers in my main alert list (which does seem to be configurable). I noticed in the BI app that there is an option to filter to show only "ONVIF Events" but it seems to return nothing. It looks like ONVIF changed over time; is this just a leftover option?