If the function is called in the main mapping, it returns the same as the main-mfd-filepath function, i.e. the full path of the .mfd file containing the main mapping. An empty string is returned if the .mfd file is currently not saved. If called within a user-defined function which is imported by an .mfd file, it returns the full path of the imported .mfd file that contains the definition of the user-defined function.
Built-in, C++, C#, Java, XQuery, XSLT 1.0, XSLT 2.0, XSLT 3.0.