Brian Ó Nualláin/Flann O’Brien/Myles na gCopaleen (1911-1966) was an Irish novelist, playwright and satirist, considered a major figure in twentieth-century Irish literature.

He frequented Mulligan’s (and indeed many other pubs in Dublin) and mentioned the Poolbeg Street saloon in his column for the Irish Times written under the pseudonym Myles na gCopaleen.

In the early 1950s, he began writing about a Lord Mayor of Dublin and these articles — with the mysterious word ACCISS prominently displayed — eventually led to Flann being removed from the civil service.

In one of the columns, Flann mentions a party he held (though the story appears to be fantasy) at which, Jack Grealish was among the invitees. Grealish knew the writer well and referred to him as Flann in conversation.

Grealish worked for the Irish Press and brought the future US president, John F. Kennedy to Mulligan’s for a drink in 1947.

The mystery of the acronym ACCISS is explained with great flair by Val O’Donnell in this video. Click on the picture below to unravel the ACCISS mystery…