Command Papers search
"Command Papers are Parliamentary Papers presented to the United Kingdom Parliament nominally by command of the Sovereign, but in practice by a Government Minister. The numbering is continuous over sessions of Parliament; they are differentiated by a letter prefix:
[1] to [4222] 1833-1868/69
C.1 to C.9550 1870-1899
Cd.1 to Cd.9239 1900-1918
Cmd.1 to Cmd.9889 1919-1955/56
Cmnd.1 to Cmnd.9927 1956/57-1985/86
"The last series had the prefix 'Cm' and ran from 'Cm 1' in November 1986 to 'Cm 9756' in December 2018. The current series, the seventh, began with 'CP 1' in January 2019."
Note: The House of Lords does not generate command papers."
Sources:
(parliament.uk/about/how/publications)
(proquest.libguides.com/parliamentary)