The Software or Solution Independent Exchange (SINEX) format is used for uniform data transfer. The first version was developed in early 1995 by the SINEX Working Group of the International GNSS Service (IGS). In 2001/2002, the format description was extended in order to have a unique and independent format description for all geodetic space techniques.
Since version 2.00, new elements and more detailed specifications have been incorporated to fulfill the requirements for SLR and VLBI solutions. The current version (2.02) was published by the IERS Analysis Coordinator in 2006, and announced via IERS message 103. The complete specifications of the current SINEX format, including explanatory notes, can be downloaded here.