XFM projects can store their properties in a variety of places. They are commonly stored as RDBMS attributes which take the form of standard MicroStation database linkages. They are defined in the XFM project so the user has control over what attributes should be displayed, how domain lists are defined, and so on. In order for a project to have RDBMS attributes, a database must be associated with the project. Only one database may be associated with a project and the database must have an MSCATALOG table. For more information about MSCATALOG, see the MicroStation help.