The Council of the Consultative Committee for Space Data Systems (CCSDS) has released Audit and Certification of Trustworthy Digital Repositories, which is a recommended practice.
Here's an excerpt:
In 2002, Research Libraries Group (RLG) and Online Computer Library Center (OCLC) jointly published Trusted Digital Repositories: Attributes and Responsibilities (reference [B2]), which further articulated a framework of attributes and responsibilities for trusted, reliable, sustainable digital repositories capable of handling the range of materials held by large and small cultural heritage and research institutions. . . . .
OAIS included a Roadmap for follow-on standards which included 'standard(s) for accreditation of archives'. It was agreed that RLG and National Archives and Records Administration (NARA) would take this particular topic forward and the later published the TRAC (reference [B3]) document which combined ideas from OAIS (reference ) and Trusted Digital Repositories: Attributes and Responsibilities (TDR—reference [B2]).
The current document follows on from TRAC in order to produce an ISO standard.