The full DDI Codebook specification was designed as a superset of elements providing an extensive coverage of social science data documentation. Many DDI users expressed the need for a "lighter" version of the specification that would contain a selection of the most relevant and commonly used DDI tags. In response to these requests, a recommended set of DDI elements is provided as a good basic framework for marking up documentation. The DDI Lite version is not a separate specification, but rather a subset of the full DDI Codebook model, and it is based on the earlier DTD version, not XML schemas.
To develop DDI Lite, several other metadata standards were reviewed to select elements that appeared to be either common across standards or critical to best practice in the documentation of social science data.