Generates check digit as per ISO 7064 11,2.
The last character in the ORCID ID
is a checksum.
In accordance with ISO/IEC 7064:2003, MOD 11-2,
this checksum must be "0-9" or "X", a capital letter X which represents
the value 10.
See also
Other check:
check_all()
,
check_all_person_info()
,
check_frontmatter()
,
check_structure()
,
protocolcheck