I don't use topics/groups but https://gnus.org/manual/big-gnus.html#Group-Parameters
mentions that groups can have a posting-style parameter, so disabling the fill mode maybe can done like | (posting-style | (eval ...change-the-fill-mode-here... | ) | ) Shouldn't that apply to the whole group then? -- Take Back Control! -- Mesh The Planet! Do you GNUS too? -- Stop worrying about spam and start to score.