The prefix names the appliance and roughly where it sits in the range: SH for a dishwasher, B and a width for refrigeration, HBL for a wall oven, NIT for an induction cooktop, HGS for a gas range, W for laundry, HUI for a hood. The digits after it place the model in its series.
That is why a photograph of the plate is worth more than any description: it tells us the appliance, the series, the configuration and which parts fit, before anyone drives anywhere. And it is why we will not quote a part against a partial number — the trailing characters change what fits.