/sys$common/syshlp/helplib.hlb EDIT, /EDT, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 file-name

    Specifies the file to be created or edited using EDT. If the file
    does not exist, it is created by EDT.

    EDT does not provide a default file type when creating files; if
    you do not include a file type, it is null. The file must be a
    disk file on a Files-11 formatted volume.

    No wildcard characters are allowed in the file specification.