Number phrases

[Nicci]

What is 180 FSDFD?

[Buffy]

I could be way off with this one, but 180 feet is the standard depth to which fishermen are permitted to try to catch fish, at least in the waters off California (that's as far as my Web research took me). Any fishies below that depth of water are off-limits and safe from fishermen. So this number phrase could be something like "180 Feet Standard D____ Fishing Depth", and I don't know what the first D stands for. Or, it could be something entirely different-- this is just a guess. Are the rest of the entries in your number-phrase quiz British-type things or American-type things? That would be a clue for us.

[Buffy]

It's me again... 180 feet standard deep-fishing depth? Jansy dear, prove me wrong!!

[Jansy]

Well done Buffy, that sounds first-rate to me. Keep up the excellent work!