Since ODF-1985 the character "-" becomes a illegal character for code of program or subprogram.

To avoid error, the code should be protected by a regexp validator.

But becareful, "-" is not a illegal character for other courselist, container, orgunit, ... and may be some repositories contains data with such a code.
The regexp validator may be added only for programs, subprograms and courses ?
Or add for all ODF contents but a migration script have to be done on all ODF contents.
A script was written for programs and subprograms here : https://docs.ametys.org/fr/ametys-odf/manuel-de-mise-a-jour/migration-technique-4-0-vers-4-1.html?&foo=0.9399267513849482#N102FC