ORCID
ORCIDs usually have four groups of four numbers. An example of a person with an ORCID is John Wilbanks. His ORCID is https://orcid.org/0000-0002-4510-0385. That is also the web address of the page about him, on the ORCID website. His ORCID can also be written as "ORCID: 0000-0002-4510-0385". Sometimes an ORCID has an "X" instead of a number at the end. An example of this is Nick Jennings's ORCID. His is https://orcid.org/0000-0003-0166-248X. The final number (or "X") is a check digit.