When browsing the bidding history on a specific lot, the list of recent bidders is shown as 'anonymised bidders' with the exception of any bids placed through your account - which would appear as your username.
When logged in to your account your bids are shown with your username, however, other users are not able to see this and you will appear as an 'anonymised bidder'.
User information/identity will never be revealed in the bidding process. We take user data and information protection very seriously at Rum Auctioneer. Further GDPR info here.