The NeXus Design page lists the group classes from which a NeXus file is constructed. They provide the glossary of items that could, in principle, be stored in a standard-conforming NeXus file (other items may be inserted into the file if the author wishes, but they won’t be part of the standard). If you are going to include a particular piece of metadata, consult the class definitions to find out what to call it. However, to assist those writing data analysis software, it is useful to provide more than a glossary; it is important to define the required contents of NeXus files that contain data from particular classes of neutron, x-ray, or muon instrument.
As part of the NeXus standard, we have identified a number of generic instruments that describe an appreciable number of existing instruments around the world. Although not identical in every detail, they share enough common characteristics, and more importantly, they require sufficiently similar modes of data analysis, to make a standard description useful. They are in the process of being defined for the NeXus standard. The definitions will be in XML using the NXDL (NeXus Definition Language) format.
Pete 15:49, 14 December 2009 (UTC): NeXus definitions TRAC ticket #3 was created to describe the items on this page. Classes that were not already described in NXDL have TRAC tickets created. The status of each of these classes is described in the comments on that page. All new propositions for classes should be described with a new TRAC ticket.
These have been voted on by the NIAC and so are official NeXus definitions
In this case the need for a particular definition has been identified, an editor has been assigned and some detailed discussions have taken place; however the definition has not yet been voted on by the NIAC and so could still undergo modification.
These definitions are currently being worked on and so could still undergo major revisions. When they near completion they will be moved into the Proposed category above.