glyph.auth(optional)A name or label associated with the controlled vocabulary from which the value of
                                             glyph.name or glyph.num is taken, or the textual content of the element. Suggested values are: "smufl" (Standard Music Font Layout.)
                                    glyph.name(optional)Glyph name.
                                             Value is plain text.
                                             
                                    glyph.num(optional)Numeric glyph reference in hexadecimal notation, e.g., "#xE000" or "U+E000". N.B. SMuFL
                                             version 1.18 uses the range U+E000 - U+ECBF.
                                             Value conforms to data.HEXNUM.
                                              
                                    glyph.uri(optional)The web-accessible location of the controlled vocabulary from which the value of
                                             glyph.name or glyph.num is taken, or the textual content of the element.
                                             Value conforms to data.URI.