# check that a field only has callsign characters in it
sub is_callsign
{
- return $_[0] =~ /^(?:[A-Z]{1,2}\d+|\d[A-Z]\d+)[A-Z]{1,3}(?:-\d{1,2}|\/(?:[A-Z]{1,2}\d{0,2}|\d[A-Z]\d{0,2}))?$/;
+ return $_[0] =~ /^(?:[A-Z]{1,2}\d+|\d[A-Z]{1,2}\d+)[A-Z]{1,3}(?:-\d{1,2}|\/(?:[A-Z]{1,2}\d{0,2}|\d[A-Z]\d{0,2}))?$/;
}
# check that a PC protocol field is valid text