The community does not yet have a consensus scheme for deposition of multiple-state models and supporting data (e.g., FID, chemical shift, and restraint data). Figure illustrates examples of multiplestate models in the PDB. Some were deposited as pairs of separate PDB files, while in other cases, the multiple-state models were concatenated in a single PDB file. For the separate entries, although comments describing the relationships of these pairs of PDB files may be included in their header files, it is not always clear if these multiple conformations were derived from a single or multiple sets of experimental data, and information on relative populations may be lost. Conformational collections for three of the multiple-state models illustrated in Figure were deposited as a single PBD file. In two other cases (5tm0 and 2lwa), the sets (2 or 3, respectively) of structures were reported with separate chain IDs within a single PDB file. In contrast, the individual multiple-state models reported in the single PDB file 7r95