Summarizing some recent Flow in-person discussions:
* We're going to append "(undo)" to lines in Flow board and topic history pages, but only for edits to board header, topic title, topic summaries, and posts. (When someone creates a new topic or a reply post, it's not a new revision of the Flow board; for these "Undo" doesn't work at a technical level, and the mental model should be different.)
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https://trello.com/c/slbmlcfX/675-g-9-add-undo-rollback-links-to-board-history>
* To deal with spam topics and posts, we're going to append "(hide)" (and delete | suppress for admins) to "created new topic"/"commented" lines on board and topic history pages. These will work the same as hide|delete|suppress actions do on Flow board and topic pages.
We'll append (unhide) to "xx hid topic/post" lines in board and topic history.
(I can't find the card for this)
* We're going to rename Close topic to Lock topic. This better matches what it actually does, which is prevent new posts and changes (with lots of bugs currently). To make it more obvious what Lock does, we'll remove the Reply and Edit links from a locked topic, instead of them failing on submit.
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https://trello.com/c/oSuO1E3T/692-1-change-text-from-close-and-open-lock-and-unlock>
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https://trello.com/c/yftcsYgu/706-2-when-a-topic-is-locked-the-new-close-take-out-all-reply-links-on-that-topic>
Note many use case of "This topic is closed" fit well with the Summarize topic action. People can and should put {{done}}, {{abandoned}}, {{answered}}, etc. templates and markup in a topic's summary.