Primrose Day and an unusual census entry

April 19 was for many years unofficially commemorated as Primrose Day in Britain. Lord Beaconsfield, (Benjamin Disraeli,) died that day in 1881. Primroses, his favourite flowers, were placed on his grave, at his statue in Parliament Square, and worn by admirers.

His name was coupled with that of Sir John A Macdonald, both were considered outstanding Conservative leaders. Although Disraeli was not yet Prime Minister when the British North America Act which founded Canada was approved by the British Parliament, he was the leader of the government in the Commons and so must surely have had a substantial role.

Disraeli appears in the 1881 census, taken not long before his death, listed by his title, The Earl of Beaconsfield, with occupation ex-Prime Minister. Someone in the census office was obviously an admirer. When in genealogy class they tell you the 1881 census didn't recorded deaths show them this curiosity - a snippet from the census document with a R.I.P. scrawled beside the entry.

I wonder, are there any special rules for citing marginalia?