To navigate to Threads Options, go to ACP → Setup → Options → [TH] Featured Threads and Content: Threads.
Apply prefix to featured threads - If selected a prefix will automatically be applied to featured threads. If the prefix is not available in the node containing the post it will not be applied. Additionally, the prefix will not be applied if the thread already has a prefix unless the option below is enabled.
Override existing prefix - If selected, the prefix above will override an existing prefix on threads when featured.
Show first post at top of first page in thread - When enabled, the first post will be displayed at the top of the first page of the thread.
Show first post at top of all pages in thread - When enabled, the first post will be displayed at the top of all of the pages in the thread.