When the check_val_runtime routine is added to the check_doc table to validate the running time in positions 18-20 of the 008 field of Visual Materials, the value '---', which is valid and indicates 'Unknown' is not permitted. When attempting to save the record to the server, the following error appears: "008/18/20: Value " " is not a running time.
The check_val_runtime routine is not the cause of this problem. All valid codings of the 008/18-20 are permitted by this check routine, including "---" (3 hyphens). This problem is caused by the presence of this line in tab_fix:
This fix routine converts all hyphens in all fixed fields to spaces when the record is being saved to the server, and 3 spaces is not a valid coding for the 008/18-20 position.
Either remove the fix_doc_fixed_fields routine from tab_fix, or use '|||' instead of '---' to code the 008/18-20 fixed field. Note that there is a slight difference in meaning between '|||' and '---'. The MARC21 standard says this:
18-20 - Running time for motion pictures and videorecordings (006/01-03)
000 - Running time exceeds three characters
001-999 - Running time
nnn - Not applicable
--- - Unknown
||| - No attempt to code