Google supports data-nosnippet, but not Bing, and no evidence of support for Baidu (our second largest referring search engine). <aside> seems to work well with both Google and Baidu.

My usage for <aside> is to make search engines not present a template's content as excerpt in the results, because most of our pages starts with a certain template. I patched MediaWiki to allow it and it works well (except VisualEditor doesn't recognize it and presents the HTML tag instead).

@Aklapper No, it hasn't happened for a long time (without my workaround). Presumably it's been fixed.

Hi there, thanks for your work but it demonstrates unexpected issues in mainland China.

Here is the log since I retry after the error is shown. I've removed the cookies.

I think it's something VisualEditor uses but source code editing doesn't use, so it happens only with VisualEditor.

I only encounter one such article. I guess the only problem is whoever sees them know there is a problem with text processing. That character renders as an (ugly) symbol indicating there is something wrong, usually a diamond with a question mark. See here: https://en.wikipedia.org/wiki/Specials_%28Unicode_block%29#Replacement_character