webinar attendee report - attendee details - what does 'denied' mean in this section?

Hi, 

In a recent webinar attendee report, there was a handful of attendees showing a confusing note, and I'm not able to find out in the Zoom support pages any information. Perhaps someone here can help!

This webinar was about 2 hours long and had both panelists and attendees. The attendees are 'guests', in that they aren't joining using a Zoom username or password related to the account.

In the 'attendee details' section at the bottom, is a column with the heading 'Approval Status'. And most of the attendees are shown as 'approved'. But, some attendees are shown in this column as 'denied'.  Does anyone here know what that refers to? 

I don't believe it refers to the registration status of the attendee since those folks did register and registration was set to automatically approve. It's not related to getting into the meeting, since they show as having attended the meeting, based on join and leave times. It's not related to accepting being recorded, since the meeting wasn't recorded. 

I suspect it's related somehow to something that happened in the meeting, but that's just a guess.

thanks for any help you can provide.