What the title says really
Quick google brings up BR3
@MattB you will probably know
I’ve a copy if it’s needed DM if you would like it emailed
You’ll find that it’s not as thoroughly prescriptive as AP 1358.
Correct, naval service dress regs are part of BR3.
The current version is publicly-hosted, not too tricky to find.
It is BR3 (Part 6) It can be found here
hope it helps
I’m ever the cynic, but I’d like to think that in the eleven months that have elapsed since OPs request that they’d found it