Retrieval locks

If a BASIC program is run by a user that does not have retrieval or update privileges (for a file that does and is opened in the program), and then attempts to read and/or write to that file, the program terminates with an error message. In order to read or write to such a file, users must make sure that the retrieval and update lock codes match those of the file that is opened. This is a system function and cannot be accomplished from BASIC. If the file is retrieval protected, the file cannot be opened and the program is terminated with an error message.