Interesting points made by Tailwheel and others on the multiple usernames. For some that have been contributing to Pprune for may years, it is not hard for employers to pick their style of writing and with a nudge nudge wink wink to the contributor tell him to lay off or risk a DCM. The adage that a prophet is never accepted in his own country, is true. A good post read by discerning readers overseas will often be rubbished by the local bogan clique on the Oz Pprune pages who readily recognise who the writer is.
I have no problem with those who elect to use a different name occasionally. Guilty as charged. For example, Dick Smith has the moral courage to use his birth name in all his posts yet the penalty for that is he gets unmercifully hammered just because he is Dick Smith. Would that occur if he slipped in another username instead in order to make a valid point for all readers to ponder? I doubt it.
I am sure those contributors that opt for multiple usernames would be happy to stick to one if there was a system on Pprune to entirely delete or archive old ones.