[Pazuzu]

A spec was older.

B spec has a better choice of wires side by side in the connector to deal with electrical fields. High speed data now creates some wild electromagnetic fields when two wires are next to each other transmitting data, the A-spec couldn't handle that very well.


For low-speed networks, or power only type things, it doesn't matter what order you choose as long as both sides are the same, but if *you* ever work on a cable, then in a year someone *else* does, they're going to assume that you used the B spec.