If you keep calling it DB9 everybody knows what you're talking about. They don't think you're weird and they also don't waste time talking about terminology.
It's perfectly fine for a product manager to say "DB9", but the guy who has to order the part from a supplier will probably want to use the correct terminology. If there's a mistake, it's the supplier's fault.
> Words mean things.
But might question what your wiring has to do with a 2000s-era Aston Martin.