Portico certified as trustworthy by Center for Research Libraries (CLR)using Trustworthy Repositories Audit and Certification (TRAC) checklist.
See the brief (8p.)CLR report at
Portico http://www.portico.org is a not-for-profit digital preservation service. Portico is a dark archive (and that presents some issues of concern for the audit process.) Portico, like JSTOR, is part of ITHAKA, http://www.thaka.org a not-for-profit organization
CRL http://www.crl.org is an international consortium or university, college and independent research libraries.
Portico is looking like a good choice for a domain-wide digital preservation repository that should save libraries and their host institutions from the burdens of doing digital preservation locally.