Meaning of "W01"?

[Oldhasbeen]

Hi

Can anyone make any sense of the attached - what does "W01" mean?

It's from my father's naval record.  13th Oct 1935 4th anniversary of his joining the navy.

Thanks!

[jds1949]

W O normally stands for Warrant Officer - the 1 would normally denote 1st class.Warrant Officers were the highest rated non-commissioned officers.

[Andy J2022]

While JDS is entirely correct, the evolution of the warrant officer in the Royal Navy is complicated and prior to 1973 the actual status of a warrant officer in the Navy varied over time, whereas in the Army it has remained largely the same, at least in the twentieth and twenty-first centuries. More on the Royal Navy aspects of the rank here:  https://en.wikipedia.org/wiki/Warrant_officer#Origins

[Oldhasbeen]

Not sure what to make of this - my late  father was a signalman throughout the war - see attached - he never mentioned anything about being a warrant officer

[ShaunJ]

I think it's "WSI" = war service increment.

[AncestryPete]

I think it's "WSI" = war service increment.

I'm with Shaun on that.