For the upcoming MathJax/mhchem update, I'd like to make sure that old chemistry.SE posts do not break. I downloaded 12,000 unique usages of \ce and I have been using them as test cases.

Some of the posts use \ce in an ... 'exotic' way and I'd like to fix those, so that the update does not break them. Sometimes it is just a space missing.

However, I get the error message

Edits must be at least 6 characters; is there something else to improve in this post?

Is there a way to go around this restriction? Can an administrator give me rights for smaller edits?

  • 1
    $\begingroup$ Take a look at meta.chemistry.stackexchange.com/questions/3044/…; there are usually many other things in the post that can be improved. e.g. smileys, taglines, salutations etc. $\endgroup$
    – M.A.R.
    Feb 17, 2016 at 8:40
  • $\begingroup$ In my opinion, if \ce{...} is used in an exotic way, it is the fault of the exotic users if it breaks — but mind I didn’t check what the actual exotic usages are; if they are chemical then they should probably stay. $\endgroup$
    – Jan
    Feb 17, 2016 at 17:54
  • $\begingroup$ Could you provide an example for the exciting usage? Maybe the use in such a case should be completely abandoned and substituted with a longer expression. For example, if it is used as \ce{sp^3} then it should be completely replaced by \mathrm{sp^3} and that should count as six characters. $\endgroup$ Feb 18, 2016 at 11:21
  • $\begingroup$ @IͶΔ That is very true, but mhchem is also doing us a tremendous favor at the expense of their own time. $\endgroup$
    – jonsca
    Feb 18, 2016 at 23:28
  • $\begingroup$ I think if links were posted, the community could edit them in short order. $\endgroup$ Feb 19, 2016 at 2:55
  • $\begingroup$ @Jon I agree, and an idea just hit me. What if mhchem posted the questions he wants to edit but can't in chat? I et al. will be more than happy to help. :) $\endgroup$
    – M.A.R.
    Feb 19, 2016 at 5:16
  • $\begingroup$ I downloaded 12000 usages of \ce from chemistry.SE. (Thanks for the export functionality, this helped me a lot!) There is quite some misuse (= not intended use). Like \ce{25^0 C} (quite some, you definitely need a number/unit macro) or \ce{Hg/mercury(I) nitrate~~ (0.005M)//mercury(I) nitrate~~ (0.05M) /Hg}. Some people used braces to change the parsing (and I would like to have that different) or added white space in strange ways. Most of these still render readable. Ther are only a few left that need a change. (Although I have way to go to finish inspecting the 12000). $\endgroup$
    – mhchem
    Feb 19, 2016 at 21:11
  • $\begingroup$ One thing that I would love to change: I would like to enforce spaces around reaction arrows, because readable input is a major goal of mhchem. However, I estimate 500 \ces here that would need a modification (out of the 12000). This means, I'd rather change my parser (and allow future space-less uses) than touching 400 posts. $\endgroup$
    – mhchem
    Feb 19, 2016 at 21:11
  • $\begingroup$ @IͶΔ Chat would be fine, too. $\endgroup$
    – jonsca
    Feb 19, 2016 at 23:49
  • 1
    $\begingroup$ Was I the only one using the \cf function instead of the \ce function? I thought \cf was a lighter-weight alternative for formulae when you didn't need the full equation-like capabilities from ce. I now have over 45 suggested edits to my old answers that replace all \cf usages with \ce....I'll definitely avoid using \cf from now on and as I guess a side benefit, all my old answers are showing up on the main page and getting more upvotes? I guess I'll take it...:-\ $\endgroup$
    – Curt F.
    Mar 11, 2016 at 23:18
  • $\begingroup$ @CurtF. I did not look at who used the \cf. Yes, it was the lightweight alternative in earlier LaTeX versions of mhchem. However, I deprecated it in recent versions, because using \ce just produces the same results. For MathJax, \cf is an alias for \ce. And if only a few people used it, I'd rather deprecate it in future versions. $\endgroup$
    – mhchem
    Mar 11, 2016 at 23:49

1 Answer 1


No, unfortunately there isn't a way to get around this for users without the editing privilege (2000 rep). People have proposed this as a feature on Meta.StackExchange numerous times, but it's thought that people would use it to "game" edits (not on our site in particular, but on a higher volume site like Stack Overflow, this is a problem).

So, there are a couple of things we can do. We can either put some links to particular posts in here and someone with the editing privilege can take care of them and/or look for any minor cosmetic things that can be changed. You will get the +2 rep bonus for the latter.

All that being said, on behalf of all of us, thank you and your team for all of your efforts to improve what is already an amazingly useful library!

  • 4
    $\begingroup$ I second that. And thanks again, it really helps this site a lot. $\endgroup$ Feb 16, 2016 at 23:29

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