I'll make a last post commenting on some points raised in Remius' last post above, then leave it at that no matter what, as I think I have beaten this horse to death.
First of all, Remius, the RN doesn't have 1B's because the RN doesn't have ANY letter system on their uniform system where levels are concerned: the letters only indicate if with arms/medals.
The uniforms of the RN are first "coloured" then, numbered - and that's it. So they have Blues number one's to Blues number fours, and Whites number one's to Whites number three's. Then, as an extra specifier, they indicate "with" or "without" medals, arms, etc with letters. And ALL these orders of dress are made available at the Crown's expense in some form to ALL Ratings, Pettys, Chiefs, Warrants and Officers.
So, in RN parlance equivalents would be:
RCN 1 --> RN Blues number One's A
RCN 1A --> RN Blues number One's B
RCN 1C --> RN Whites number One's WB
RCN 1D --> RN Whites number One's WC
Now, to address the constant return to trying to make the current RCN's 1C and 1D equivalent to Army "patrols". The comparison is incorrect. The idea behind the "patrols" is to give various regiment/organizations the capability to have their own, historical, regimental ceremonial dress to be worn instead of the DEU's number One's. They are an alternate order of ceremonial dress.
The RCN's 1C and 1D are not "alternate" or worn "instead" of number 1 or 1A: They are the tropical/summer version of the 1 and 1A. Like the old winter / summer dress, they are worn AS number one's during the designated summer period or in designated tropical waters.
Here is the second description from the RN on when to wear the Whites number one's, for instance: They are worn : "when required to conform with accepted international standards of dress on state or major ceremonial occasions". Note the "diplomatic" aspect of wearing it.
P.S.: I note you mention that in the RN it is the officers above Commanders who wear the high collar white jacket. That's fine with me, I'd much rather that Commanders and below, down to the most junior ratings, be provided with the RN's bush jacket White's number One's. :nod: