I was looking for firefox use flags and this site http://www.gentoo.org/dyn/use-index.xml lists a bunch of them. Including webm. But when I run the command emerge --ask firefox there's no webm use flag (set or unset...) I don't know if it is a bug in portage, which does not recognize webm flag or if obsolete documentation. Probably second, so I'm posting in this section.
Some versions of firefox still have the flag, some don't. The available flags are different for each version of the ebuild, so you should just trust your emerge output and not worry about that online list.
Humm... so I think it's really a bug in documentation, since it should have at least a p.s. making the observation, like: package flags description firefox webm** Use system media-libs/libvpx for HTML5 WebM video support. Obs.: ** some versions of this package may not have this flag, depending on your ebuild Do you agree?
The useflags differ as changes are made, some options such as webm are no longer optional while other options have been added that are not in older ebuilds. Documentation should reflect such info to prevent confusion. Feel free to open a documentation bug requesting that it be clarified.
