There are no newer specifications as far as I know. If you want simply to construct file URI objects from URI strings, use the normal URI constructor. See the Cwd manpage . This method return a file name. It maps from the URI name space to the file name space of the indicated operating system.
Some systems use a different form for names of directories than for plain files.
Use this method if you know you want to use the name for a directory. If the file system has device, volume or drive specifications as the root of the name space, then it makes sense to map them to the authority field of the generic URI syntax. Another common use of the authority field is to encode the host that this file name is valid on. This use will be in conflict with using it as a device specification, but can often be resolved for device specifications having characters not legal in plain host names. There are usually many URI that map to the same file name.