FITS headers

A review is being made of the FITS header keywords at the NOT as defined in the document ``FITS observation files at the NOT'' (Saskia Prins, 2004). Beyond some specific changes that have occurred since that time, we are cross-checking the headers with the new FITS standard version 3.0 (2010) and the updated ESO Data Interface Control document version 5 from 2011. An update to the original FITS document is made as a reference for FITS headers at the NOT, and as a working document for the actual implementation of new FITS headers. A first draft of the document is expected to be circulated among the staff in the near future.