XtDisplayInitialize uses them to build the initial resource database. One argument to MrmOpenHierarchyPerDisplay is a list of UID filenames, each of which represents either a full pathname or a name to be substituted in a file search path. MrmOpenHierarchyPerDisplay calls XtResolvePathname to search these paths. When it uses a search path, MrmOpenHierarchyPerDisplay looks for files first using a suffix of .uid and then using a NULL suffix. As with the initial resource database, UID files can reside in different directories depending on the language environment.
L is replaced by the display's language specification.
U is replaced by the current filename from the list of filenames passed as an argument to MrmOpenHierarchyPerDisplay . MrmOpenHierarchyPerDisplay returns an ID that identifies the list of open UID files for subsequent calls to routines that load data from the files. On each request to load data, MRM searches the list of files in order. This ordered list of open files is the UID hierarchy. The program can retrieve data from the hierarchy until it calls MrmCloseHierarchy .