In the context of format recommendations, the TEI has the same status as XML: too general to be a meaningful recommendation. The TEI Guidelines, together with the surrounding infrastructure (Stylesheets and dedicated utilities) is a toolkit for creating formats (also formats that serialize a standard).

By rule of thumb, centres should expect that each TEI document submitted to them is either accompanied by the ODD file, or conforms to one of the publicly available ODD specifications (either a named TEI out-of-the-box customization or a publicly documented extension), preferably bearing the stamp of a standards body, or encoding established best practices.

An ODD file defines the semantics of a TEI format, by means of prose, datatype restrictions and Schematron constraints. It is the basis for creating document grammars (schemas) that the conforming TEI document can be validated against. Schemas can be derived e.g. with the help of TEI Stylesheets or Roma, XML editor add-ons, etc.

In the context of CLARIN and LRT applications, the following TEI-based formats are recognizable:

• ISO/TEI Transcriptions of Spoken Language -- serializing the corresponding ISO standard
• DTABf -- Deutsches Textarchiv Basisformat, used at BBAW
• ISO LMF -- TEI serialization of the Lexical Markup Framework (part 4 of the 2020 LMF standard)
• TEI Lex0 -- an OASIS standard for the encoding of (a.o.) retrodigitised dictionaries, maintained by DARIAH
• I5 -- tool format of DeReKo (Deutsches Referenzkorpus), used at IDS Mannheim

The above list is not meant to be exhaustive. While the above items would generally qualify as TEI extensions, the environment of the TEI Guidelines defines a series of restrictions on the overall TEI schema, referred to as 'templates' and meant as bases for further customization, as well as three fully-defined and maintained customizations: TEI Lite, TEI simplePrint, TEI Tite.

For the purpose of metadata descriptions, free-standing TEI headers can often be found of use.