Thanks all for your responses.
Andy has it correct!
(tab) being equal to "^t" = tab key on keyboard
An simple example of a line is :
John,Smith,123,456
John,Doe,123,456
Until EOF
needs to be:
John(tab)Smith(tab)123,456
John(tab)Doe(tab)123,456
until EOF
The comma between 123,456 can't be...