Thanks to excellent context clues I've recently learnt that 'anon' is used as an abbreviation for 'anonymous'. I used to think the word meant 'coming' (as an answer to a call), as used by Shakespeare (see e.g. "Romeo and Juliet"). I wonder if the compilers of the Oxford English Dictionary have found out about the new meaning of the word 'anon'. My definition is probably already labelled archaic.