Difference b/w Beta & Stable AND Incognito mode

I'm so sorry to bother you if this is discussed already, but I can't seem to find it. Could someone please tell me what exactly is the difference between the Beta & Stable versions? Are you trying out some new software or configuration on the Beta version? If yes, please tell which. And is there a way to selectively remove an entry from the recent files section? If not, please tell me how to put in a request for this feature. I really need this feature and it absence is the reason I have to use keep other media players installed on my laptop with already scarce storage.
Thanks in advance

Beta contains the latest changes. It simply hasn't been tested extensively yet.

You can submit feature requests at:
https://trac.mpc-hc.org/timeline?daysback=3&authors=&ticket=on&ticket_details=on&changeset=on