-* `scope_copy`: Copy the scope (private/unlisted/public) in replies to posts by default.
-* `subject_line_behavior`: Allows changing the default behaviour of subject lines in replies. Valid values:
- * "email": Copy and preprend re:, as in email.
- * "masto": Copy verbatim, as in Mastodon.
- * "noop": Don't copy the subject.
-* `always_show_subject_input`: When set to false, auto-hide the subject field when it's empty.