https://mailarchive.ietf.org/arch/msg/apps-discuss/1_a06NU8z...
> 1) I feel that /host-meta is too casual of a name and prone to collisions. It matches /^[\w\-]+$/, which I think is a subset of a fair number of sites' usernames."
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> i.e. put something ugly and weird in there, like a semicolon, to minimize the chance that it interferes with people's existing URL structure.
Fun bit of history!