Meta means discussion of the discussion itself instead of the actual topic of the discussion.
Why do we need a meta category?
Meta is where communities come together to decide who they are and what they are about.
Meta is for the folks who enjoy the forum so much that they want to go beyond merely reading and posting, to work toward improving our community together. Meta is where all leadership and governance forms, a place for debate and evaluating direction.
Meta is also community memory, documenting the history of your community and its culture. There's a story behind every evolution in rules or tone, and these shared stories bind communities together. Meta is the home for all the tiny details that make your community unique: its terminology, its acronyms, its slang.
What kinds of meta topics can I post?
Which topics should we allow and encourage? Which topics should we
What sort of replies are we looking for? What makes a good reply
versus one that is out of bounds or off-topic?
What are our standards for community behavior, beyond what is defined
in the FAQ?
How can we welcome new members of our community and encourage them?
Are we setting a good example for the kinds of discussions we want in
What problems and challenges does our community face, and what can we
do about it?
How should we moderate our community, and who should the moderators
be? When should we flag posts?
How do we publicize and grow our community?
How should (or why did) the rules change?
(Source: the amazing Discourse team's Meta category)