The _expand.pub utility expands a file when an error is encountered. It is called with the channel number the file is opened on and the error (either an !ERROR=1 or an !ERROR=2) that occurred. (An !ERROR=1 will cause an expansion of the record size. An !ERROR=2 will cause an expansion of the number of records.) The _expand.pub utility then expands the file by 10 percent in the direction of the error. After exiting, the channel for the file is opened to the expanded version of the file.