A common form of address seems to be to leave it out altogether. People are frequently listed as David Smith, or just D Smith. I do some medical work using a computer system that requires that a title be used. The problem is that frequently the letters that arrive requesting medical appointments seem to skip the title and hospital notes seem not to show them. I think that the public services got tired of having to correct the titles all the time that they decided to skip them to save time. I'm inclined to change my system to match, although I'm sure that to the older generation in particular it sounds rather rude.