When a fourth value is snagged, the value in B is lost. In this mode, no measurements are taken. Button 2 rotates between the three memories recorded in mode 11. In some sense, there's not much to support. The meter either works or it doesn't.
Operation is very straight forward.
I did call to find out about the input characteristics as discussed above and was, well, not impressed. After 2 minutes, the line drops dead. I call back. Same female passes me on to Ray quickly this time. I ask Ray about input specs.