ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / XidML is an open, vendor neutral, XML based standard for the FTI community used to capture the metadata associated with flight test instrumentation and data acquisition networks. This paper discusses the difference between metadata and meta-metadata, how these concepts apply to XidML and an optional schema, XdefML. The paper also describes how Settings and their validation may be applied to a Generic package definition. Some examples are given of how the current version XdefML can be leveraged to auto-generate graphical user interfaces that are both feature rich and incorporate sophisticated error checking and data validation.