An identifier(s) (ID), if any, other than the organization's Unique Protocol Identification Number or the NCT number that is assigned to the clinical study. This includes any unique clinical study identifiers assigned by other publicly available clinical trial registries. If the clinical study is funded in whole or in part by a U.S. Federal Government agency, the complete grant or contract number must be submitted as a Secondary ID. [ https://prsinfo.clinicaltrials.gov/definitions.html ]

Other identifiers besides the Trial Identifying Number allocated by the Primary Registry, if any. [ https://www.who.int/ictrp/network/trds/en/ ]