The Trusted Digital Repositories: Attributes and Responsibilities (TDR) enumerates characteristics of a sustainable digital repository for large-scale, heterogeneous research collections. TDR addresses the seven attributes such repositories must have; discusses requisite responsibilities at both the higher organizational/curatorial level and the operational level; looks at how repositories can be certified; and makes key recommendations.
The seven attributes identified in TDR include:
0. OAIS compliance
1. Administrative responsibility
2. Organizational viability
3. Financial sustainability
4. Technological and procedural suitability
5. System security
6. Procedural accountability
The Trusted Digital Repository Model to the left illustrates how these attributes are related to each other. Some are nested within a "Digital Archives Border" while others will be external to the digital archive itself—or even the host institution. OAIS compliance is an inherent attribute that underlies all the others.
In subsequent sections of the tutorial, we address each component, highlighting the organizational 
, the technological (0101), and resource dimensions ($$$$).
We added the Digital Archives Border to the model. This element was not present in the TDR document, but it is important for two reasons: a digital archive might be managed by more than one organization, and one organization may manage more than one digital archive. The document comes close to defining a one-to-one relationship between an organization and a digital archive, which is often not the case.