This is in a Boddington's brewing record from 1946, showing the permitted output and actual output:
Permitted output was set as a percentage of of production over a 12-month period. For example, in 1947 it was based on a brewery's output in 1945-1946:
"Beer Cut in New YearI've found a couple of articles in the newspaper archive relating to permitted output, such as the one above. But only for the later war years and a couple of years in the late 1940s. Nothing for the early years of the war. I'd be dead grateful if anyone could point me in the direction of wher I migh find this information.
A reduction in the allocations of sugar to manufacturers has necessitated a cut as from January 1st in the beer output, almost equal to nine pints out of every barrel, announces the Brewers' Society.
The permitted output of beer for each brewery will be reduced to 82 per cent. of the standard barrelage produced from that brewery in the 12 months ended March 31st; 1946. Since May. 1946. the permitted output has been 85 per cent.
The reduction is being made to secure the saving of 23 per cent. in the consumonon of sugar which the Minister of Food announced some weeks ago is to be applied yo all sugar-using industries."
Staffordshire Sentinel - Saturday 20 December 1947, page 1.