Most meta pages belong in normative namespaces within the domain discussed. However, sometimes an entirely separate domain is created for discussions that would otherwise distract typical users. For instance, Wikimedia the organization discusses issues with its organization dogma on meta.wikimedia.org not Wikipedia. Some political party wikis also operate separately from the domain name signifying the party itself. It's also common to use other media, usually yahoogroups or other mailing lists to discuss concerns that don't seem to be easy to discuss in wiki format.