When it is and is not acceptable to edit someone else's post

Question

TL;DR: In what circumstances is it ok (by CGCC and politeness standards) to edit directly a post (be it challenge, answer, sandbox question, etc), assuming the edit is done in good faith?

I know people can rollback edits and further edit a post, but in the meantime that goes from the unwanted edit and the correction, many things can happen. What is more, the OP doesn't get notified when the post is edited, so it could take a long time before the OP realizes the post was badly edited.

Context

I was under both ends of the "edit without consulting the OP" situation (bullet points below) and wanted to clarify it for me and for other users

• [I edited without consulting OP] Recently I wrote a challenge and, later on, I added a couple of test cases. A particular user had a Python answer (a language I know how to write in) and so I took the user's TIO link, added the test cases and edited the answer to include the new link. I thought I was not doing any harm.

  Of course I managed to edit at the same time as the user and so, they edited to golf the question and I submitted my edit which overwrote the user's golf. The user talked to me and asked I leave a TIO link next time, without directly editing the question. In hindsight I think the user was completely right and it would've been even easier for me to just drop the TIO link in the comments.

• [my posts were edited without my consent] I wrote a couple of sandboxed challenges and I didn't include any test cases, as I wanted a bit of preliminary feedback first; a user edited both my challenges and for each, did a combination of

  1. create reference programs and include TIO links as if they were mine;
  2. create a test case section with text written in the first person, so effectively impersonating me;
  3. addressing some of the feedback left in the comments (which was fair feedback) but that was more than a trivial change;

Answering this

I am not sure I have the "authority" to make this statement, but I'd suggest people mention one situation per answer and the community votes to agree/disagree with the answer.

The answer should clearly state if the situation mentioned is a "not ok to edit" situation or a "it is ok to edit" situation, along with a short description, in the header.

Rules here take effect if they have at least five upvotes and have at least twice as many upvotes as downvotes.

Related but 6 years old already and only one answer.

Answer 1

It is not ok to edit to golf an answer

if you are going to golf someone else's answer (this doesn't happen much, it is usual to see people leave a TIO link with the golfed version or a hint on what to do).

Answer 2

It is OK to rectify a question's tags.

i.e. add relevant tags and remove irrelevant tags.

Answer 3

It is ok to edit to fix code formatting

If you are fixing formatting issues, for example multi-line code that isn't properly formatted:

---

s = "hello world..?"

print(s)

to

s = "hello world..?"
print(s)

---

or if you are fixing mathematical formulas/variable references that lacked formatting and thus blend in too much with the text, e.g.

• you will receive three integers a, b and C

to

• you will receive three integers a, b and c

Answer 4

It is ok to edit to fix typos

If you are fixing minor typos or any other minor, self-contained, English-related issue that you won't change the meaning of the OP's sentences.

Consider pinging the OP if you feel tempted to change more than a couple of words, as matters of style, preferred spelling, etc are all subjective. (c.f. Mitchell Spector's comments below)

Answer 5

It is NOT ok to remove rules from a challenge, even if they are listed as things to avoid when writing challenges

Answer 6

It's not okay to add a leaderboard to a challenge.

We have a consensus on this topic to not add leaderboards to challenges. Although that concensus is about a bot, humans can nevertheless still employ the described behavior.

To have bots that autonomously make edits is annoying, intrusive, and error-prone.

Mobile users have 3 huge codeblocks to scroll through before they can see the answers, especially for challenges with only a few answers. It's not really necessary, plus it makes the question harder to navigate through.

Quoting JoKing:

@a'_' Can you stop adding leaderboards to challenges? Especially ones with only a few answers.

It's not really necessary, plus it makes looking at questions on phones more annoying

Answer 7

It's not okay to modify code.

This is based on a merging of this answer and this answer.

In general, never modify the code part of the answer, even if it employs one of the Standard Loopholes.

Given an invalid answer, commenting and flagging are the appropriate actions to take.

Answer 8

It is not OK to edit someone's post if they disagree with the edit.

This is a network-wide rule. If a post-owner disagrees with your edit, and the edit is important, get a moderator involved.

Answer 9

It's okay to add an online interpreter link for an answer.

Adding an online interpreter link allows other people to test their answers, without having to go to the online interpreter themselves. So if you find it hard to test their answers, feel free to edit in an online interpreter link to make it easier for others!

Answer 10

It's not okay to add an explanation of the code

That should be left to the author. Explaining the code is a sensitive area. You can't be sure that your comments exactly reflect the author's intent. There may be subtleties you are missing when interpreting the code written by another.

Answer 11

It's OK to revert edits made in violation of the rules described here.

Fairly obvious, but needs stating.

Answer 12

It is okay if you are adding syntax highlighting to a post.

In this post, the most upvoted answer (i.e. the consensus) says something along the lines of syntax highlighting making posts a lot more easier to read.

Answer 13

It is OK to remove "non-competing" from answers in languages that post-date the challenge

See https://codegolf.meta.stackexchange.com/a/14989

Answer 14

It's OK to edit a post when the post author explicity allowed this type of edit

For example:

• A KOTH challenge can state bot authors may edit the leader-board themselves when adding or modifying bots after the challenge has closed.
• Challenge might offer a bounty for a specific extra challenge and request the bounty offer be crossed out when someone completes it.
• A answer chaining question that allows edits might include a link to the latest post and request new posters to update this link themselves. Not saying this is a good idea but if OP asks this making the edit would be OK.
• If OP specifically asks a second person to keep a post up to date then all edits are OK if according to the agreed on parameters.

Answer 15

It's not okay to edit someone else's off topic post.

In fact we've already reached a consensus on this. If you edit an off-topic post to make it well-received, OP will think that it is okay to post these kinds of questions on this site. Instead, people should notify the OP about why the question is not well recieved. If really neccecary, another user should take control over the post and post the on-topic modification on a separate post.

Answer 16

It's not okay to remove outdated content from a post

Just comment and let OP handle it. You should never do it yourself.

Answer 17

It is OK to incorporate rules or clarifications to a challenge posted by the author in comments into the question body.

Answer 18

It is not ok to edit if you are removing background information

It's not okay to remove the question's background information, even if the background informattion is not relevant to the main challenge. If OP thinks the background information makes the challenge clear, allow OP to add that.

Answer 19

It is OK to edit someone's cops state to Cracked

In case the author is away

Answer 20

It is OK to correct the header of an answer

Examples:

1. Correcting the score of an answer to match the challenge's scoring rules
2. Adding header markup to an answer whose header lacks it
3. Adding a bytecount to an answer that lacks one
4. If the rules of a challenge require some answers to be marked non-competing, adding that annotation to answers that lack it

This is not intended to be an exhaustive list.

Answer 21

It is ok to edit to add MathJax

If you are fixing mathematical formulas/variable references that could be improved by changing to MathJax:

E.g. from

• The kinetic energy E is 1/2*mv^2

to

• The kinetic energy is \$E = \frac12 mv^2\$

Answer 22

It is not ok to edit if you are adding substantial text

If you are going to add whole sentences, paragraphs or sections, it is not ok to do it without the OP being aware of such a change.

Especially if you have to impersonate the OP:

e.g. if you are adding a sentence that clarifies the meaning of, say, a mathematical function, that would be less inappropriate than adding whatever sentence in the first person.

Answer 23

It is OK to Add an Explanation for SBCS¹ languages

Above there's already a contradicting answer. I also put my own thoughts on allowing explanations for all languages which was ill-received. Here's I propose only for a certain class of languages:

I can see the case for disallowing the addition of explanations to more conventional & verbose languages like C/Python/Ruby/Haskell, as there's far greater ambiguity with explaining them. They don't require consulting an encyclopedia given reasonable familiarity with the language.

On the other hand, for the terse, SBCS (usually golf) languages – the fun ones! – the case is different. Think 05AB1E, Jelly, CJam, Pyth, Golfscript & even APL/J... Vim?! Many of them must be read by consulting the documentation for each character. More importantly, doing so is entirely unambiguous. For instance, see 05AB1E's codepage here. The first 5 lines:

╔══════════╦═══════════════════╦════════════════════════════════════════════════════════════════════════════════════╗
║ Command  ║  Elements Popped  ║                                     Description                                    ║
╠══════════╬═══════════════════╬════════════════════════════════════════════════════════════════════════════════════╣
║ ǝ        ║  a,b,c            ║   Replace the element of 'a' at index 'c' with 'b'                                 ║
║ ʒ        ║  a                ║   Filter 'a'. Keep the elements where the result of the code is 1. Usage: ʒ CODE } ║
║ α        ║  a,b              ║   Absolute difference of 'a' and 'b'                                               ║
║ β        ║  a,b              ║   Convert 'a' from base 'b' (arbitrary)                                            ║
║ γ        ║  a                ║   Split 'a' into chunks of equal adjacent elements.                                ║
╚══════════╩═══════════════════╩════════════════════════════════════════════════════════════════════════════════════╝

Closing Case

An explanation in such languages usually just means pasting the definition of each character from the doc's help page or wiki. This may be done, and verified, with little to no expertise in the language and make a world of a difference, from impenetrable gobbledy-gook to perfect English.

Everyone trudges through the same braindead labor to understand a code-only answer in a language like O5AB1E, painstakingly looking up each symbol. If one person does the work for us, no one else has to!

¹ The exact rule to categorize the class of languages I'm referring to is a work-in-progress. I'd appreciate any suggestions on improving it, but for now I think at least the idea is clear enough!

Answer 24

It is OK to Add an Explanation

Above there's already a contradicting answer. Originally, I was posting this as a comment. Decided to submit my own answer and let the community decide:

While there are subtleties that may be missed, I feel strongly that some explanation is better than no explanation. I'd hope we'd all prefer to live in a CGCC populated with well-explained answers and minimal code-only answers.

Since we already have a consensus on code-only answers being low-quality and undesirable, it seems to post an answer without one is to implicitly give permission to the community to add it.

Fine Print

• An explanation may not be edited, one must comment to correct. That would assume better knowledge, risk losing the aforementioned 'subtleties' and require the edit's approver to know the language.

• If they add a note along the lines of Will add explanation, usually waiting to see if it garners attention before slaving away, one shouldn't edit until 3 days have passed since they posted.

Note

I'm trying this out generally. However, I can see the case for conventional & verbose languages like C/Python/Ruby/Haskell, as there's far greater ambiguity with those.

If downvoted into oblivion, I will post another answer specifically for terse, SBCS (usually golf) languages like APL/05AB1E/CJam as that seems far less controversial. For example, given /⍨⍳4 → 1223334444 adding the following hardly seems controversial:

⍳4        ⍝ Integers 1..4
   ⍨      ⍝ Duplicate argument on each side
     /    ⍝ Replicate each element `n` times