A draft ITU-T definition of the term 'open standards' has been
developed by ITU-T's group of experts on intellectual property rights (IPR).
deemed necessary to do this to avoid confusion given the various
different interpretations of the term. This way when 'open standards'
are referred to in discussion, it is clear exactly what is being talked
about - at least in ITU-T.
The draft definition can be seen here.