Inclusion of comma or dash in custom field label precludes match on import

If the label field for a select, multi-select, ADVMulti-select multiple choice option for a custom data field includes comma (,) or dash then it is impossible to match with that field label during import of contact data.

The problem is made worse because the data passes the verification step with no error given. During the import step, the custom data field is skipped, though the rest of the record import proceeds with no problem. But again, no error is given at the import step.

So the user is unaware that the import has succeeded but the data in the custom field was silently omitted.

The solution for now is it import using the custom field value rather than label, so at least there is a workaround.

I suspect that that there may be more problem characters than comma and dash but I have tested specifically for those and they are definitely a problem.