Oh, it's so difficult being a thicko! I didn't find your example at all instructive. H-HANDICAPPED is self explanatory and I kinda guess that B-BUKH means bulkhead. But there is no legend for C the only letter that appears on a seat. And what do the * and B in the margin mean?

I realise that since they differ by airline it will be impossible to list them all. But a few more clues would be really help us retards.