There are now two additional keyword arguments to chimera.fileInfo.register: category and dangerous. The category should be set to one of the built-in categories or one you invent. The categories are meant to help organize all of the file types chimera can open. A set of default categories has been created, chimera.FileInfo.X where X is DYNAMICS for a molecular trajectory (amber), GENERIC3D for generic 3D objects (vrml, bild), SCRIPT for command scripts (python, midas), SEQUENCE for molecular sequences, STRUCTURE for molecule structure (pdb, mol2), SURFACE for molecular surfaces (grasp), and VOLUME for volume data. The dangerous flag defaults to True for scripts and false otherwise. You can override that default by giving the keyword. So far, the categories have only been added to the default file types in the chimera module and to the Midas module. Please update your uses of chimera.fileInfo.register in the extensions you maintain. - Greg