(In reply to Jon from comment #37)
> As stated above external links were removed as part of the typography beta
> feature. Actually, not a single person wrote about this on the talk page
> (https://www.mediawiki.org/wiki/Talk:Typography_Update) during the 6 months
> it was live. This evidence leads me to believe that they are /not/ important
> and it is the basis for removing them.

However, anyone who used a wiki (like English Wikipedia, which has such rules at https://en.wikipedia.org/wiki/MediaWiki:Common.css and https://en.wikipedia.org/wiki/MediaWiki:Vector.css) with local rules would not have seen any difference.

Thus, it's a valid question how many people who used the Beta feature saw a visible change to the main (PDF and HTTPS seem like the biggies for article space, with the audio being used a decent amount, but not as much, but I don't have data) icons.  If a tiny number were affected, then "not a single person wrote about this" is not a convincing argument.

I think English Wikipedia Beta users saw neither change, since PDF is at [[MediaWiki:Common.css]] and HTTPS is at [[MediaWiki:Vector.css]].

However, it is certainly true that we are not going to be able to do dedicated research for every change, and this may be one such example.  I agree that this feature affects both readers and editors, and we need to consider the impact on both.  Having tools to do A/B tests on readers would certainly help, but it wouldn't solve everything.

It can definitely be iterated on regardless.  In particular (if we proceed without the format-specific icons), there should be at least one follow-up change to do the following:

1. Remove obsolete FIXME comment from externalLinks.css.
2. Release notes
3. Fixes from https://gerrit.wikimedia.org/r/#/c/123817/3/skins/vector/components/externalLinks.less .  Note the point about div#content on the left, and might as well do the formatting fix on the right (space before right paren) since there needs to be a commit anyway.

Marking open again and assigning to Jon.