Hi, I work on SBML (Systems Biology Markup Language) at Caltech. We are thinking of proposing a new XML MIME media type. When learning about the process for getting a new IETF-tree media type approved, I was strongly advised to consult the members of the ietf-types and ietf-xml-mime discussion lists for advice before diving in. So here I am. I'll appreciate any advice you can give me, especially any that saves us from making some stupid mistakes that the biological modeling community will regret for years to come. Please forgive me if I reveal my ignorance in some questions below. First, a little background. SBML is an XML format for representing systems of biochemical reactions. Making it a MIME media type would enable browser-based simulation tools to conveniently download, run, and edit models. Work is now beginning on a web infrastructure to make it easy for biological researchers to share models on the web, download models used in published papers, etc. Two "levels" of SBML have been defined so far. Specifications, including the XML schemas, are at: http://www.sbw-sbml.org/sbml/docs/papers/sbml-level-1-version-2/sbml-level-1... http://www.sbw-sbml.org/sbml/docs/papers/sbml-level-2-version-1/sbml-level-2... We are thinking that the ideal name would be either: application/sbml+xml or: model/sbml+xml Now, here are a few questions. 1. Would it be a bad idea if we used RFC3236 (The application/xhtml+xml Media Type) as a model for the document w write? I'm hoping that we don't need to explain the full semantics of SBML in the RFC, since there are already some weighty papers that do that (referenced above). At only 8 pages, RFC3236 seems like a model of simplicity and clarity that we would like to emulate. Or is it possible to get even simpler? Some of the docs I found for XML MIME media types seemed to do little more than list the name of the type and who submitted it. 2. We are thinking of including required parameters of "level" and "version". Anything to watch out for here? Is this a wrong idea? SBML has multiple levels to enable different simulation tools to interoperate at different levels of complexity and sophistication. Each level can come in different versions. More levels are planned. 3. Is it completely stupid to even consider model/sbml+xml? The other model/ media types have been for spatial models. SBML is primarily used for spatial models of reactions that occur within biological cells, and has some notions of spatial relation, but an SBML model does not necessarily have the minimum 3 orthogonal dimensions specified in RFC2077. We're wondering if SBML is still within the spirit of the model/ top-level content type, though. RFC2077 speaks of economic models, behavioral models, and so on, and seems to encourage a situation where modeling tools might work successfully on models from radically different domains. 4. Any other advice you'd care to offer? Thanks in advance for your assistance, Ben -- Ben Kovitz Systems Biology Workbench (SBW) Development Group, Caltech http://www.sbw-sbml.org bkovitz at caltech.edu