As of July 2015, the Prototype History Research tool contains over 3.7 million descriptions of persons, families, and organizations (identity descriptions) derived from more than 6.6 million EAC-CPF records derived primarily from archival resource descriptions and original authority records. The source data was provided by a large number of contributors. The SNAC identities are linked to holdings in more than 4000 repositories. “Featured records” provides random selections of identities that also match entries in Wikipedia, and these are typically for well-known (or at least relatively well-known) persons. These persons also tend to be well-documented in the primary resources and thus constitute “strong” identities. However, many of the persons, organizations, and families in the Prototype History Research tool are weakly identified, which is to say, the available evidence does not establish a strong, reliable identity.

The linked resource descriptions represent all resources that are identifiably related to the identity, either as a creator or a subject of the resource. Holdings of hundreds of repositories, large and small, are represented in these resource links. While the representation of holding repositories and known, available resources is substantial, researchers should not assume that the links represent all available resources. As additional repositories contribute data to SNAC, the number of linked descriptions of holdings will continue to grow. There are always new discoveries to be made, as the vast majority of resource descriptions mention only a fraction of the persons, organizations, and families represented in a collection, and not all collections in any given repository have been processed and described.