ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / A few years ago XidML was introduced as an open XML standard for capturing the meta-data associated with flight test instrumentation (FTI). This meta-data schema was broken down into elements for Parameter (name, range, units, offset-binary), Instrument (name, serial number, misses-to loss), Package (bits per word, words per minor-frame, rate) and Link (name, type) and so on. XidML remains one of the only published schema for FTI meta-data and with XidML 3.0 many simplifications have been introduced along with support for nested tree structures and a single instrument schema allowing anyone to define the validation for instruments from any vendor. This paper introduces the XidML schema and describers the benefits of XidML 3.0 in particular. It begins by giving a brief description of what XidML is and describes its history and motivation. The paper then outlines the main differences between XidML-3.0 and earlier versions, and how the XidML schema has been further refined to meet the challenges faced by the FTI community. As an example of usage the FTIManager software developed at Eurocopter will be briefly presented in order to illustrate the XidML ability to describe a multi-vendor FTI configuration.