CAS numbers are not public domain, are they?
" Work created before the existence of copyright and patent laws also form part of the public domain . The Bible and the inventions of Archimedes are in the public domain. However, copyright may exist in translations or new formulations of this work. " [ Wikipedia ] As posted by Tony is the Chemical Abstract Service (CAS) discouraging using their CAS services for assigning correct CAS numbers to structures for any third party database. Wikipedia is a source of structures, which is public domain due to its GNU FDL . Still, this does not imply that any translation of structures, e.g. CAS numbers, are in the public domain, too. Honestly, this raises a serious problem for curating CAS numbers on Wikipedia and this raises indeed the question, if they should not be dropped from Wikipedia, and any other information source, at all? Is it not better having no information, than having wrong information? A CAS number is for me only one certain translation of a chemical structure....