A paper published in the Macromolecular Crystallography volume of Methods in Enzymology describes the procedures used for structure validation and processing by the PDB. The article is an overview of the deposition process, including descriptions of the checks and reports generated by ADIT. The validation and standardization of all the data in the PDB are also outlined.
J. Westbrook, Z. Feng, K. Burkhardt, H.M. Berman: Validation of protein structures for protein data bank. Methods Enzymol. (2003) 374: 370-85.