There is a really nice video from the Swedish Airforce museum where a former fighter pilot tests their JAS39E simulator that gives REALLY clear details about the MFD (timestamped to 4:35, English subtitles available).
At 5:10 the pilot selects a target and gets a gray square with info that states “UN-ID” in the center for the yellow unidentified targets.
If it’s closed you can either message the Technical Moderators here on the forum and ask them to re-open it or you can use the “report” function on the bug report site to ask them to re-open it so that you can add more information.
Click to reveal general guide for contacting moderators
You can find all the teams and the areas they handle listed here: (Who is who and Reporting Procedure). If you don’t get an answer within a few days you can add more moderators from the list to the original message instead of sending a new message (that way you preserve the date of the message and it doesn’t look like a new request), adding one of the moderators to the message every 2-3 days or so until you get an answer.
Please do not to add the seniors until you have tried all other regular moderators, the Seniors likely won’t answer unless they are added and pinged by the regular moderators but if you’ve added all the regular moderators with no answer then you can add the seniors.