[Fedora-packaging] How can packages require a pre-release version?

http://fedoraproject.org/wiki/Packaging:NamingGuidelines#Non-Numeric_Vers... So, this has been a problem for a while for me, but I'm just now getting to bring it up... Basically, packages need to be able to require "xulrunner 2.0 beta 11" but that's impossible with the current guidelines... Essentially, the number that gets incremented is _before_ the pre-release, and unfortunately there's no time machine available to determine how many increments will occur before the next tarball update, so packages can't do Require: xulrunner > 2.0-0.19.beta11.fc15 Require: xulrunner < 2.0-0.22.beta12.fc15 since we might just go straight to 2.0-0.20.beta12.fc15 or we might need 20 rebuilds of beta 11. And depending on the specific NVR is suboptimal too. What I want to do for the XULRunner case specifically is change it to: xulrunner-2.0-0.0.beta11_1.fc15 // first instance of beta 11 xulrunner-2.0-0.0.beta11_2.fc15 // rebuild of beta 11 xulrunner-2.0-0.0.beta11_3.fc15 // another rebuild xulrunner-2.0-0.0.beta12_1.fc15 // first instance of beta 12 xulrunner-2.0-0.0.scm20110209_1.fc15 // scm snap from Feb 9 2011 xulrunner-2.0-0.1.beta13_1.fc15 // first instance of beta 13 So, the first 0 would signify a pre-release, the second 0 would be used as sort of a "prerelease epoch" if needed as shown above, and it would be followed by the pre-name, and then a release. Normally, a hyphen would precede the rpm release of a tarball, but we can't have that here due to the fact that we're putting some of the version information in the release, so I think underscore works just as well here, and is better than a dot. This would allow packages to do things like Require: xulrunner >= 2.0-0.0.beta11 Require: xulrunner <= 2.0-0.0.beta12 Thoughts? (Note: since we're currently at -0.19... in rawhide, I'd of course start with 0.20 for this round of pre-releases, but would start with 0.0 for the next set of pre-releases)