From “Manual of library economy, 3d and memorial ed.” by James Duff Brown, an anecdote about (I believe) Brown himself:

Quiet as he was in many ways, he was of a social disposition,
a trait which found an outlet to some extent at the Library
Association, of which he was a councillor from 1890 to 1911;
but for closer purposes of camaraderie he founded, with Mr Jast,
the well-known Pseudonyms, a dining-club of librarians and
their friends, which had its origin in the ‘nineties, and flourished
for many years. The meetings were held in various Bohemian
restaurants in Soho, professional and literary topics were debated,
and Brown reported them in The Library World. The reports
had little relation to the actual proceedings, and few people
were more entertained, and, incidentally, astonished at their
own wittiness (as reported) than the Pseudonyms themselves.