Developers & Publishers

As states, territories, the District of Columbia, and the Department of Defense Education Activity (DoDEA) move from widespread adoption of the Common Core State Standards to implementation, there is a need to appropriately identify and link assets using a shared system of identifiers and a common XML representation. The Council of Chief State School Officers (CCSSO) and National Governors Association Center for Best Practices (NGA Center), working closely with the standards authors, have released an official, viable approach for publishing identifiers and XML designation to represent the standards, consistent with their adopted format, as outlined below.

  1. Canonical identifiers for individual standards (revised 5/21/13) - Rather than force a decision among three competing options, the NGA Center and CCSSO have decided that the following three options have distinctive values and should be published together simultaneously.

    Unique identifiers are needed for humans and technology to refer to individual standards in a consistent manner. Three sets of canonical identifiers, as detailed below and now readily available here on, will maintain fidelity to the published and adopted documents, while acknowledging the wide variety of use cases, users, and systems needing to reference the standards:

    1. Dot notation including those from the published and adopted standards documents, e.g. Math.6.EE.1, useful for conversation and displayed with the text of a standard. Published identifiers will necessarily follow a different nomenclature in mathematics than in English Language Arts (ELA) and literacy, because the standards documents themselves follow a different system in each discipline. These differences have been adopted by states
    2. De-referenceable Uniform Resource Identifier (URIs) at the domain, e.g. or Matching the published identifiers, these deferenceable URIs allow individuals and technology systems to validate the content of a standard by viewing the web page at the identifier’s uniform resource locator (URL). The NGA Center and CCSSO strongly recommend that remain the address of record for referring to standards.
    3. Globally unique identifiers (GUIDs), e.g. A7D3275BC52147618D6CFEE43FB1A47E. These allow, when needed, to refer to standards in both disciplines in a common format without removing the differences in the published identifiers. GUIDs are unwieldy for human use, but they are necessarily complex to guarantee uniqueness, an important characteristic for databases, and are intended for use by computer systems. There is no need for educators to decode GUIDs.

    All individual standards and lettered sub-items; all anchor standards in ELA; and all practice standards in math, as well as cluster headings in math, have received identifiers. We have not provided numbers for reading headings such as “craft and structure” or “key ideas,” since these headings were intentionally left un-numbered and since they do not strictly define different domains in reading. In math, however, cluster headings have an important design function in organizing the subject matter and in adding important meaning to the individual content standards; math cluster headings are also proving crucial in implementation efforts. Therefore math cluster headings have been given identifiers (such as A, B, C, for example). By this means, the identifiers preserve links between standards and clusters, which is necessary to ensure that applications using the system can preserve the meanings that arise from considering the cluster headings and the individual content standards in conjunction with one another.

    In the process to develop the identifiers, key clarifications were made and are briefly summarized below. A memo with full details of the changes made during the identifier development process is available here.

Naming the ELA/Literacy framework

There is a tendency in the field to shorten The Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science and Technical Subjects to “ELA” and this term does not properly encompass the Standards for Literacy in History/Social Studies, Science and Technical Studies. Thus, the standards framework as a whole is referred to as “ELA/Literacy,” and the field is strongly encouraged to adopt this entire phrase.

Different hierarchies

The Common Core State Standards for Mathematics and the Common Core State Standards for English Language Arts and Literacy in History/Social Studies, Science and Technical Subjects are different in many ways, and the hierarchies from the framework to the component level reflect some of those differences. Clusters are part of the hierarchy in Math but not ELA/Literacy. A single level in the identifiers represents strand and domain for ELA/Literacy, whereas strands do not exist in Math. To require conformance in the hierarchical structures in the two frameworks would ignore the fundamental organizational characteristics of the two standards documents and would compromise the integrity of the architecture of each set of standards.

The official hierarchical nomenclature is as follows:

Math ELA/Literacy
Initiative Initiative
Framework Framework
Set Set (optional)
Grade Strand+Domain
Domain Grade
Cluster Standard
Standard Component (optional)
Component (optional)


In ELA/Literacy, the Domains, such as Reading Standards for Literature (RL) fully reflect the Strand (Reading), so this level of the hierarchy reflects the Strand and Domain combination.

In Math, Set refers to the sets of content and practice standards. In ELA/Literacy it is an optional designation for the anchor standards.

Framework names and Revisions

To differentiate the Common Core State Standards from state standards (in other domains or as part of the optional, up to 15 percent standards additions), CCSS is now added to the front of the dot notation identifiers. For example, what appears in the PDFs as RL.2.1 is officially CCSS.ELA-Literacy.RL.2.1. It is assumed that educators will continue to use the shorter RL.2.1 in conversation, but the official dot notation identifier will contain the CCSS component.

The publication year of 2010 is provided in the metadata and XML for the standards but is not included in identifiers. Any future refinements to the CCSS will be appended with a revision number, for example CCSS.ELA-Literacy.RF.4.4r2, or, reflects the second revision, or third version of CCSS.ELA-Literacy.RF.4.4.

XML and metadata

The XML representation of the standards and the embedded metadata within the HTML pages is available at To access the XML and metadata, append “XML” to any of the identifier URLs. The XML and metadata represent the intent and language of the standards and go no further. Hierarchies and relationships that exist in the adopted documents are reflected in the data files, but other data points not specifically codified are not. The XML file follows the Common Education Data Standards (CEDS) schema, also used by Schools Interoperability Framework Association (SIF). For more information about that schema, please visit

CCSS Official Identifiers and Metadata Project XML Version


The Partnership for the Assessment of Readiness for College and Careers (PARCC), the Smarter Balanced Assessment Consortium (Smarter Balanced) and the State Educational Technology Directors Association (SETDA)— working in partnership with CCSSO— completed a collaborative, state-centric project (“Granular Identifiers and Metadata for the Common Core State Standards” or GIM-CCSS) to facilitate the long-term technical implementation of the Common Core State Standards (CCSS) in a digital format that meets the diversity of stakeholder needs in the field, while preserving the conceptual and structural integrity of the standards.

The project offers a more fine-grained digital mapping that is needed to fulfill the goals and objectives of the multi-state assessment consortia, as well as for other purposes including the digital alignment of instructional materials and professional development resources.

The technical work undertaken by GIM-CCSS was very specifically limited in scope to developing digital references to the conceptual statements already contained within the CCSS documents and to preserving the logical structure dictated by the standards authors. It builds on the prior work of CCSSO and the NGA Center by publishing more detailed, digital, machine-readable identifiers and metadata for the Common Core. More information on this project can be found at