The TEI Special Interest Group on Libraries has released version three of the Best Practices for TEI in Libraries: A Guide for Mass Digitization, Automated Workflows, and Promotion of Interoperability with XML Using the TEI.
Here's an excerpt from:
There are many different library text digitization projects, serving a variety of purposes. With this in mind, these Best Practices are meant to be as inclusive as possible by specifying five encoding levels. These levels are meant to allow for a range of practice, from wholly automated text creation and encoding, to encoding that requires expert content knowledge, analysis, and editing. The encoding levels are not strictly cumulative: while higher levels tend to build upon lower levels by including more elements, higher levels are not supersets because some elements used at lower levels are not used at higher levelsâ€”often because more specific elements replace generic elements.