This (see photo).
Just bought one, was about to question its calibration, then I look on the web and every unboxing vid or photo shows them sitting there reading -4 to -10 counts fresh from the box. Spec is 5. Mine does it on the 8V range (shorted or not), and 20A range. mA shows 0. mV range is expected to show a few microvolts out, but the 8V range is 100uV counts (no better than your average 3.5 digit meter). Perhaps I was expecting better, because I have the handheld version of this meter, and it always quickly settles to 0 on VDC, even after 14 years. I know the Fortune chips on these DMMs are not rated up with HP and Keithley, but they do have a competent autozero at 80000 counts, and generally seem to function competently and linearly.
There's a REL mode, but I suspect having 400uV of offset when measuring lower voltages is going to bug me, especially as there's no lower range in the standard input impedance and protection VDC mode (without switching over to uV). Fortunately microvolts is just a button press away (the reason I got it basically - the rotary switch of the handheld is one thing I can't automate through the interface, having sniffed the protocol out a decade or so ago), but still.
I wonder what it is.