ADS-B characteristics

[flightlogic]

I post this in safety, because I am of the opinion that ADS-B enhances safety.
I want to better understand what I see on the displays though.
Today, I had flight ID selected ON. One of the targets displayed the letters VFR under the target symbol and trajectory trend line.
I am, of course, used to seeing the N number of targets and airline designations on the high flyers. Or in many cases, no ID at all.
Is this going to become common to see just the identifier VFR in lieu of a registration?

[BobTurner]

If you are seeing unidentified mode C or mode A targets which are being fed into the ADSB system, there will be no N number. Mode A targets will have no altitude. How your display handles them is display-specific.
Also, UAT aircraft can hide their N number if they choose.

[Jesse]

If you are seei a squawk code of 1200 and no N-number, the target has UAT out and hidden registration. If you see just the target with no info, it is likely a mode a/c only with no ads-b out.