Active volume: A volume in the candidates queue becomes active whenever someone reviews it. Active volumes are given precedence by the queuing algorithm because work has already been done on them. A volume ceases to be active when all parts of the review process are complete.

Admin: An admin is someone entitled to see all project dashboards, statistics, and user information in order to run the project, assess performance, and track activity. An admin cannot override the constraints of the system to change the rights status of a volume.

Attribute: A rights code is composed of two parts. The first half is called the attribute, and it represents the copyright status of the work and facilitates access control. Examples of attributes used by CRMS are “ic,” “icus,” “pd,” “pdus,” and “und.” There are twenty-six attributes (as of this writing), though most are not used in copyright determination. A list of attributes can be found at

Candidates (pool): The candidates pool is a subset of volumes within HathiTrust whose metadata (date and place of publication, country of origin, current rights, etc.) indicate they are within scope for a defined CRMS copyright review project. The candidates pool will trend toward zero as work progresses; however, it may remain level or even increase as HathiTrust ingests new volumes that match the scope. Candidates are updated each night by a query run against the HathiTrust Rights Database. In some cases, volumes are dropped from candidates due to a change in eligibility often stemming from a correction to their bibliographic metadata.

Catalog ID: The catalog ID is a unique identifier assigned by HathiTrust and Zephir that joins together related volume IDs of a particular work in the same edition. Each catalog ID in Zephir may have one or more than one volume ID associated with it, depending on how many copies of that work in that same edition are in HathiTrust. This relationship can be used to assign rights codes to duplicate volumes; however, a catalog ID may also represent volumes in a multipart monograph. In this case, the catalog ID does not indicate volumes that are exactly the same and should not be used for rights code inheritance without determination of individual parts.

Conflict: A conflict occurs when two reviews for a volume disagree on one or more critical pieces of information that would affect access to the work. For example, two independent reviews of the same work are in conflict where one reviewer selects “public domain” and the other selects “in copyright.”

Enum/chron (enumeration and chronology): These are standard metadata used in library catalogs for serial publications and multipart monographs. The presence of enum/chron metadata in a record prevents inheritance of rights codes in CRMS because volumes that are part of a multipart monograph may be subject to different rights.

Expert reviewer: An expert reviewer is a reviewer who is specially trained to adjudicate conflicting reviews. Experts are selected from top performing reviewers to address conflicts generated by reviewers.

Exported determinations: Not all final determinations are sent to the HathiTrust Rights Database. Exported determinations are a subset of final determinations that meet criteria for export.

External admin: An external admin is a liaison from a partner institution that may not have authorization to perform copyright determinations but requires access to performance statistics of reviewers from their institution in order to make supervisory decisions.

Final determination: A final determination is the collective result of all reviews done on a volume (including, if necessary, an expert’s adjudication). It is the result when that process is complete.

Inheritance: This takes place when a CRMS determination is exported to the Rights Database.

Inheriting volume(s): Inheriting volumes are all duplicate copies of a work (in that particular edition) in HathiTrust. After a source volume’s rights code is exported to the HathiTrust Rights Database, volumes eligible for inheritance are automatically given the same rights code.

Inserts: Component parts in a larger work that were written or created by other authors and may be subject to different copyright terms. Illustrations, articles, quotations, lyrics, and diagrams are examples of “component parts” that could turn out to be inserts. An insert could be an extensive part of a larger work, but even a brief insert can be significant. The presence of an insert is one of the more common reasons why a CRMS reviewer may decide a volume should be set aside as “undetermined.”

Multipart monograph: A work composed of more than one part in which the parts have been published over a span of time (usually several years). A multipart monograph can be a special problem in copyright determination because the parts of the work may be subject to different copyright laws—for example, a US work in which the first part was published in 1920, the second part in 1925, and the third in 1930. As a result, the individual parts have to be reviewed independently, even though technically they belong to the same work.

PageTurner: A HathiTrust application that enables authorized reviewers to view scanned page images. CRMS embeds a version of PageTurner in its interface, but it is a separate application owned and maintained by HathiTrust. HathiTrust access and authentication modules confirm when a user should have authorization to have access to it. If a request for access does not come from an approved IP address, PageTurner will restrict access to works in the public domain. For more details about the application, see

Priority: Priority codes route a volume through the CRMS system so it will be displayed to the appropriate user and in some cases restricted from view to other users. The majority of volumes are given Priority 0, which enables any reviewer to see them. Some volumes receive higher priority to ensure they will be reviewed more quickly and/or by a more experienced reviewer.

Reason: A rights code is composed of two parts. The second half is called the “reason,” and it accounts for why the volume was given that copyright status. There are eighteen “reasons” (as of this writing) accounting for a number of different situations. A list of reasons can be found at

Review: A review is an individual reviewer’s judgment about the copyright status of a work. The reason for that judgment is stored in the system with a corresponding rights code. Depending on how a volume moves through the CRMS process, two or three reviews may accrue before a final determination is reached.

Reviewer/advanced reviewer: A reviewer is a person authorized to perform copyright determinations. A reviewer is moved up to the status of an advanced reviewer after demonstrating consistent and reliable understanding of the process. Advanced status requires less oversight of a reviewer’s work.

Rights code: A shorthand term representing both the attribute and reason code of a determination.

Rights database: The repository of rights information for each digitized volume in HathiTrust. The Rights Database should not be confused with the CRMS database, which is a separate repository that includes more detailed metadata necessary for rights research. For further details, see

Source volume: A source volume is the specific scan that has undergone manual review. A volume ID represents the source volume. Once one copy is reviewed in CRMS and becomes a source volume, then all the other copies associated with that particular catalog ID in Zephir may become “inheriting volumes,” provided there is no indication of enum/chron in the catalog ID.

Status: Status codes indicate how far a volume has progressed through the review process and, to some degree, which path that volume is taking through the system (e.g., Did both reviewers agree or disagree?).

Super admin: A super admin has the highest level of permissions and may override system logic in order to review any volume, not constrained by the scope of any given candidate pool. Formal legal training is a consideration in granting this role. The system developer also has this role.

Swiss option: The Swiss option is an alternative to invalidation, which an expert reviewer may employ during adjudication to grant a neutral mark to a nonconforming review. Without this option, any reviews that do not match the expert’s would count as errors in the reviewer’s personal statistics. A Swiss option neutralizes the issue and avoids invalidating either reviewer. It is primarily useful in situations where there is complexity or a judgment call beyond the bounds of routine work.

Validation/invalidation rate: A validation rate is the percentage of an individual’s reviews that either matched other reviewers’ judgments or are deemed correct by experts. The statistic is represented as validation in the personal display. For the management team, it displays in the converse as invalidation. The validation rate is a broad measurement to test how closely a reviewer is aligned with the CRMS review process. Adjudications where an expert elects to apply the Swiss option do not count against a reviewer’s validation rate. Instead, they are counted separately, influencing neither validation nor invalidation.

Volume: A volume in HathiTrust is not a “book” in the normal sense of that word but a unit of measurement indicating the unique scan representing one physical item. In line with common library binding practice, it may represent a discrete monograph, a single volume from a monographic series, or several items bound together. Scans of the same work but from different physical copies are treated as unique volumes, and each one receives its own volume ID. Copyright determinations are made at the volume level.

Volume ID: The volume ID is an alphanumeric identifier assigned by HathiTrust and Zephir to a volume (e.g., mdp.39015005731453). Each scan representing a different physical copy of a work is assigned a unique volume ID.

Zephir: A bibliographic metadata management system the California Digital Library developed specifically for HathiTrust. Prior to Zephir’s launch in fall 2013, HathiTrust had relied on Mirlyn, the University of Michigan’s online catalog.