Parameter Definition MIB-source-file A comma-separated list of MIB definition files. The standard extension is .MY, but you can specify any valid OpenVMS file name. You must specify the full file name. subtree The text name for the root of your MIB definitions. This parameter must be enclosed in quotation marks. This name is used in generating names for template C modules and also for the names of the files themselves: subtree_tbl.c and subtree_tbl.h.