Is it possible to force all real names ( which I require for registration) to be used as the display name?

Currently the system uses the chosen login name ( user name) as the display name and I have to change this manually for each member.

Sorry if some of you don't agree but my site is on ethical business and I really don't think it suitable to be having a discussion with roger rabbit or blue boy wonder ( if you get my gist)

Any ideas please???

You can use this hook http://community.invisionpower.com/index.php?app=downloads&showfile=6139 to let the user type the real name. You'll only need to change the language bit from "Display Name" to "Real Name".

This is not a Custom Profile Field.