Trying to leave an edit summary gives me this error message:

transcription below

Comment reserved for system use. Please use an appropriate comment.

This occurs both for anonymous and logged-in edits, for answers and for questions, using my phone (Chrome, Android) and computer (Chrome, Windows 11 Home). However, I can still perform logged-in edits, as long as I omit the edit summary. I am located in the Western United States.

  • Possibly related to Was the minimum character limit for questions increased to 300 recently? (MSO)? The site setting for minimum question length apparently got reset. Maybe in a similar way the edit reason field got some of its constraints changed.
    – VLAZ
    Commented Jun 25 at 16:23
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    Note that it does allow empty edit summaries.
    – Barmar
    Commented Jun 25 at 16:28
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    @Barmar Not if your edit summary has to be at least 10 characters. Commented Jun 25 at 16:31
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    @ElementsInSpace I haven't run into that requirement, is it a per-site setting? I've been able to enter empty summaries on Stack Overflow.
    – Barmar
    Commented Jun 25 at 16:33
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    Hey! I reported the same exact issue to Meta Super User 3 minutes faster than the original poster here. Commented Jun 25 at 16:36
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    Someone else reported the problem on MSO — and I found it there pointing to this entry on MSE. Commented Jun 25 at 16:38
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    @Barmar I think you have to leave an edit summary on any site where you don’t have the edit posts privilege. (Unless it’s your own post.) Commented Jun 25 at 16:40
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    @VLAZ: I tried to edit a question from 2012 y'day and couldn't submit it because of the increased character count. That sort of thing is irritating. I'm not about to invent 175 characters of extra material for a valid (just about) but succinct question. I suppose I could use HTML comments <!-- Garbage text here ... --> (IIRC) but I shouldn't have to do that when doing minor clean up of an antique question. Commented Jun 25 at 16:40
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    I think this should go into the "Hot Meta Posts" on Stack Overflow and probably most other sites. Commented Jun 25 at 16:48
  • @Mithical any reason you removed the link from the image? Does it have any downsides? The image isn't clear in the post as it is being resized by the browser, and clicking it to see the full image is useful, unless I'm missing something here. Commented Jun 26 at 10:49
  • @JonathanLeffler HMP is for per-child meta and automatic based on certain criteria. Unfortunately, there's no way to automatically feature questions on MSE to select sites, other than... well, featured it. Commented Jun 26 at 11:36
  • @Sha - Linking an image changes how it's treated by different ways of consuming the page content, and it's usually not necessary to have it be a link if you're not using a different size image or something similar. In this case, the relevant text in the image is also reproduced in a quote. It's not a big deal either way, though.
    – Mithical
    Commented Jun 26 at 14:51

2 Answers 2


Caused by a build that deployed a couple hours back (and was, unsurprisingly, reported almost immediately). That change has been reverted.

(It's not immediately obvious to me from reading the code change why it caused this error, so unfortunately, these are all the notes you're gonna get on this one!)

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    That build was reserved for system use. Please use an appropriate build. ;P Commented Jun 25 at 21:04
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    @Michael This witty comment reply was reserved for system use. Please use an appropriate comment reply.
    – Slate StaffMod
    Commented Jun 25 at 21:07
  • Still happening on SO on reloaded page, not reverted yet.
    – philipxy
    Commented Jun 26 at 0:14
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    You said you won't comment further, but I still have to ask: what sense does it make for any comment text to be "reserved for system use?" (I asked this on the SO dupe as well.)
    – tripleee
    Commented Jun 26 at 6:46
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    @tripleee In a number of places, error messages are used to catch states that shouldn't happen, particularly when open text fields are involved. For example, that string that is never supposed to be surfaced to userland? Well... maybe someday, someone will find a way, on accident or by bug. So we use validation checks to prevent undesirable outcomes. When they fail, an error is surfaced to the user. Under normal circumstances, that error shouldn't be surfaced to a user by design - the system generates, then validates, the string - so it barely matters what it says.
    – Slate StaffMod
    Commented Jun 26 at 13:24

This looks like a SE bug. I was just about to post the same issue, and it looks like at least one other has reported this as well .


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