Because spaces and multiple @'s are a bad idea.
# Make *sure* that 'preprocess' comes before any realm if you
# need to setup hints for the remote radius server
authorize {
+ #
+ # Take a User-Name, and perform some checks on it, for spaces and other
+ # invalid characters. If the User-Name appears invalid, reject the
+ # request.
+ #
+ # See policy.d/filter for the definition of the filter_username policy.
+ #
+ filter_username
+
#
# Do checks on outer / inner User-Name, so that users
# can't spoof us by using incompatible identities