I filter a lot of email at work, and got into a really hellish game battling hierarchical labels. To restore myself to sanity, and to corral them into some sort of system, required inspiration: IRC. Specifically, the prefixes used on its channels (chat rooms). These prefixes vary from most important to least, and they sort in the following order as well.
& — Local channels
RFC28111 describes the & prefix as indicating a channel “local to the server where they are created,” or, not shared on the rest of the network. I’m using this prefix exclusively for internal email sent by a human:
&Basecampfor discussion posts.&Everybodyfor company-wide emails.&Recruitingfor anything about candidates.- Internal lists which disallow external email.
# — Shared channels
Unlike the previous prefix, #-prefixed channels are shared across the network. This fits well with email coming in through a mechanism I can control, sent by either a robot or a human:
#Feedbackfor support emails from humans.#Automatedfor daily statistics reports.#GitHubfor notifications I’ve opted into.- Internal lists which encourage external email.
+ — Unmoderated channels
The + prefix signals a channel without moderation. The parallel I draw is with public discussion or announcement lists:
+Librariesfor library announcements.+Applefor developer updates.- Any regular old mailing list, really.
RFC1459 established it first, of course, but the wording is barely intelligible:
There are two types of channels allowed by this protocol. One is a distributed channel which is known to all the servers that are connected to the network. These channels are marked by the first character being a only clients on the server where it exists may join it. These are distinguished by a leading ‘&’ character.
Every copy I’ve found has the same grammatical horror. ↩︎