Might others be interested in a forum setting that disables the feature of selecting text in a post to quote in reply?
I understand this feature descends from long tradition, dating back to the early days of electronic mail. And I see the technical work and additional UI work that Discourse has put into progressing it as a tool. But I’ve also become ever more convinced over time that outside established relationships of trust, reading a reply, especially a disagreeing reply, built half of a patchwork of your own words, readily evokes emotions akin to those felt by witnesses under cross-examination.
Basically, inline response is a power tool, and one more prone to carnage than clarity in many circumstances.
Especially for forums that expect lively debate among members who don’t know each other well, I’d appreciate a clear way to express, or even enforce, that folks are expected to speak in their own words. I might even go so far as introducing a check to show a warning, like the reply-too-short warning, when a user attempts to quote the post they’re replying to in a Markdown blockquote.
There is a user preference to disable selection quote, which was put there for the (bizarre, IMO) users who reflexively select text as they read. I was quite surprised to hear about this because it seems… unhinged to me … but a lot of people apparently do this and pushed for it at some length in 2013 when we launched?
Beyond that, enforcing “no quoting of other posts, ever” would need to be a plugin, I’d think. And clever users would be able to get around it in a multitude of ways, sort of the same way users can generate blank posts if they reaaaallllly want to, though we do try to strongly discourage it.
Personally, I’m far more interested in a way of projecting that original posts are the forum expectation. Not an ironclad technical prohibition on doing so. Though I’d embrace a technical feature that makes that expectation part of the guidance new users receive, in passing, as they interact with the UI.
There are a couple ways to do this, in terms of user education:
customize the pop-up overlay guidance that appears for your first two topics and first two replies, to mention this rule
customize the default “type here” text that appears in the editor to mention this rule
mention it in the “about this site” pinned topic that you fill out during the site setup wizard on initial install, and appears as the first visible “what the heck is this place” topic for all users (though pinned topics will un-pin after you’ve read them, for logged in users)
there’s a lot of quoting functionality built in which you can potentially hide via simple display:none; override CSS rules, such as the quote button in the editor, the quote button that pops up when you select text, etc
Are there any communities that you’re aware of which enforce this rule, either through software or through public moderator / community rules?
I definitely get how this can be way too much. Let me post an example. All text below this point is a PARODY. I am only assuming this style for the sake of showing a BAD EXAMPLE of what you DON’T WANT
How interested are you? Interested enough to pay for the effort?
What do you mean by projecting?
Define “original”. Nothing is original.
Maybe for some folks but not all!
No such thing exists; there’s no way to make it ironclad.
Which reminds me, one passing thought I had a while ago was a warning when you include too many quotes (from the same person, where you’re nitpicking them to death) in a post, but it’s such a difficult thing to enforce in an algorithm…
When I lived in Russia, a friend made a point of sharing an old textbook from his schooldays in the Soviet system. A whole book lambasting the United States of America and its capitalist crony-nations … with all the source readings translated from American newspapers.
I would personally work hard to find a way around prohibitions on quoting replies. In most cases, it can provide much needed context for responses, especially when you are synthesizing ideas and posts from different users.
Frankly, some Discourse instances rely on the quote function for editing and feedback to content creators, who take their work to fellow users for exactly that purpose.
But if it doesn’t work for an instance, then an option to decrease reliance has been provided:
Some forums need it. Others don’t want it. I belong to a few of both.
@codinghorror pointed out that it’s a user-specific interface option to disable the feature. But that doesn’t do anything site-wide, nor to communicate the expectation of original posts.
Did you try his suggestions here, both for sitewide (the last one) or user education (the first three)? What were the results?
There is also the option to have some well-respected users (your community’s “influencers”) mention the expectation directly: “I don’t want to quote because…,” “just using this one quote to contextualize my thoughts,” etc.
You could also consider adding a “model post” topic, with exemplars, templates, or some fuzzier guides described as “best practice” for this or that type of topic or reply.
What type of guided modding are the users in the community most receptive to (e.g., converts most effectively to behavior change)?
Interface nudges and interface limitations. Which is why I brought up the too-short-reply feature.
I am going to try some notes in text in one of the communities I admin. But I’d still like an option to make the user-specific quote flag forum-wide. And I like the idea of a plugin that detects too many quotes or too much quoting from the prior message.
If you don’t like the idea of Discourse without the feature, that’s fine. Nobody’s brought up removing functionality or changing defaults.
All text below this point is a PARODY. I am only assuming this style for the sake of showing a BAD EXAMPLE of what you DON’T WANT 
Did you try his