In 1.2.x you go to borrowers detail page, then click on modify, and you can set the flags on the modify screen.

You should be able to do the same in 1.9.3 ..

moremember.pl has a link labeled 'modify user flags' (in the default template) which takes you to member-flags.pl, but that only offers settings for access: 'circulate books, set user permissions, etc'. -- Owen