`I contacted the ILO about using this classification structure on Wikipedia. I thought it could be useful, as a recognized category structure. They were very helpful, and granted me ``(hereinafter called the Licensee) a non-exclusive, non-transferable worldwide licence to: reproduce the structure and framework of the ILO International Standard Classification of Occupations (ISCO-88) for use in the online free encyclopaedia Wikipedia (www.wikipedia.com), accessible by the general public (hereinafter called the end-users):``   However, one of the conditions of the licence was that: The rights are granted on the understanding that any republication by the end-users, in whatever form, without the written consent by the ILO, is prohibited; the Licensee undertakes to so inform its end-users;   Although there were other restrictions, I think this one may preclude using the structure at all. I will follow this up over at the copyright issue pages.  `