The ORCID iD is a unique, persistent identifier
free of charge to researchers.
Checks whether the ORCID iD has the proper format and a correct checksum.
The ORCID iD must be in the format 0000-0000-0000-0000 where the last
digit can be a number or "X".
Empty strings are considered valid to allow optional ORCID iD.
See also
Other validation:
validate_citation(),
validate_email(),
validate_language(),
validate_license(),
validate_ror(),
validate_url()