Hi Phil, On Thu, Mar 21, 2019 at 03:06:56PM +0100, Phil Sutter wrote: [...] > I was talking about the "osf name . osf version" part. If not optimized, > each osf expression would perform a database lookup and return different > parts of the fingerprint. > > Or did I miss your point? Oops, sorry. I misunderstood. I don't think we should split this in two separated selectors. Matching on 'osf version' alone itself does not make sense to me. I think it's useful to match on: * genre * genre:version * genre:version:subtype anything else for this, I don't have a use case. We can achieve something similar to what you suggest in your 'osf name . osf version' example via: osf version { "Linux:2.4", "Windows\*" } Thanks!