The only global mechanism for format typing in current widespread use is the MIME(Multipurpose Internet Mail Extensions) Media Types [5] registry operated by IANA (InternetAssigned Numbers Authority) [11]. However, for many digital repository operations MIMEtyping does not provide sufficient granularity to disambiguate important format distinctions,whether based on versioning or profiling. For example, both a tiled RGB TIFF image usingLZW compression and a striped bi-tonal TIFF image with Group 4 compression are typed withthe same MIME identifier: image/tiff. Similarly, the entire PDF family – PDF 1.0 through 1.4,PDF/X-1 through 3 (ISO 15930), and the proposed PDF/A standard [1] – are all typed with asingle identifier: application/pdf. In both cases, the variant digital objects may undergo differentparallel workflows dependent upon the specifics of their internal structure or semantics. Tofacilitate this, the proposed format registry will allow typing, and unambiguous identification, atarbitrary levels of granularity.

It is important that the registry is able to provide detailed authoritative representation informationabout formats. The MIME registry has varying requirements regarding the level of disclosure ofthe specific internal structure of MIME types. In particular, for registrations made outside of theIETF tree such details are “encouraged but not required” [6]. Additionally, publication of thistechnical information is accomplished through the RFC (Request for Comments) process, whichrelies on discursive text meant for human consumption. The proposed format registry seeks bothto develop an appropriate trust mechanism to encourage the deposit of detailed representationinformation about proprietary formats, and to make such information available in standardizedhuman and machine-readable forms, using controlled vocabularies to the fullest extent possible.

Challenges There was little success in attracting dues-based members. There was some interest in using the BRIDGE ID and its associated data as an open data resource, by not for pay. Beyond the original partners, we found few organizations and companies that wanted to use the BRIDGE ID for data interoperability to keep databases synchronized and current. It was hard to penetrate the market for unique organizational identifiers among established and well-funded vendors such as LEI, DUNNS, and a large number of country-based identification systems world-wide. The level of manual effort necessary to curate and deduplicate country-based organizational data internationally far exceed our funding expectations and challenged our sustainability.