When checking the tidy-font-bug at svwikipedia I find a lot of signatures like:
<font color="green">[[User:Example|Example]]</font>
Is it important that we fix these?
Topic on Help talk:Extension:Linter
It depends on how important it is to your wiki that that example continues to show up in green.
Usually, I've noticed that this error is introduced on talk pages because of user signatures. So, if these links lose their custom colour and display in standard blue, then, you can ignore it and fix it with a bot at a later point. I personally think it is not a big deal. But, it depends on your wiki's community obviously. On dewiki, for example, they were / are primarily concerned with fixing lint errors in the Article namespace and aren't worried about archives and user pages and talk pages as much.
Note that even after we replace Tidy, this list of lint errors will continue to show up - so, you can fix some of these lower priority issues like talk pages gradually.
Alright. In that case I'll focus on non-talk pages. Thanks!
dewiki has been described correctly. We focus on articles and first row project pages.
The font issue as described above influences the appearance of a personal signature only, perhaps of a user inactive for a decade now. The link is blue, not green as intended, and it works. This is under personal responsibility of that user; if they wanted long term stable design, they should not use a tag obsoleted in 1998 and put the decoration inside the brackets to be sure that the colour takes precedence over link styles.
multiple-unclosed-formatting-tags is a completely different business. If there is written intent<s>ional<s>ly now all remaining text on page catches strike-through and is not readable any more. Here we fix talk pages as well, but only since that is affecting talk contibutions of innocent users rather than the villain.
@Skalman https://sv.wikipedia.org/wiki/Anv%C3%A4ndardiskussion:Nirmos#Suggestion_for_Linter_fixes has some tips for how some html5 misnesting issues could be fixed.
@SSastry (WMF), thanks for the suggestion. I'll probably fix a few of the errors, but it feels like a bot would actually be needed...
One hacky fix is to update the templates to change the '' to <i> and ''' to <b> tag. That ensures that the quotes in the pages won't conflict with the i/b tags in the templates. That will cause the HTML to be <i><i>..</i></i> ... or <b></b>..</b></b> .. but that won't cause any problems.
I think that is how itwiki folks tackled this kind of issue.