Unicode Variation Selector-15 and some of my tears

Summary

From my phone, I noticed that my website was displaying footnote backlink glyphs as emoji in my RSS reader. It had not always been this way. I opened the same page from a desktop browser and saw what I expected to see: a text-like pictograph, in my article body’s font face. No emoji to be found. I checked the HTML document source: <a href="#fnref:1" class="reversefootnote" role="doc-backlink"> &#8617; </a> The RSS feed XML contained the same. So, that can be presented as either text or an emoji? &x8617; is an HTML representation of the Unicode codepoint U+21A9, Leftwards Arrow with Hook. This led me to many relevant threads, pastes, and blog posts in which others had observed similar issues with Leftwards Arrow with Hook and other, similar navigation-decoration characters. We were all reacting to U+21A9 as rendered without a Unicode standardized variation sequence specified. So it’s up to whatever program is rendering U+21A9 to decide what to do. Which version, the text or the emoji, should U+21A9 render. I found the correct solution and some less correct solutions to this issue. Before I describe them, I want to explore a slightly larger problem introduced by variation selectors. The downstream effects For meta-ish content characters like backlink glyphs, the way forward is clear for people who are technical: fix and/or configure the thing that builds your web pages. Or complain in the direction of the people who can fix and/or configure the thing. For many of the other characters, it’s more complicated. Many of these characters are used in body content to be expressive. Rendering the text presentation instead of the emoji presentation, at worst, could be a mistranslation. The technical standard (see the emoji-data links, and specifically emoji-data.txt) lists over 1,000 Unicode codepoints that have both text and emoji presentations. Codepoint Glyph As text(+U+FE0E) As emoji(+U+FE0F) U+00A9 © ©︎ ©️ U+00AE ® ®︎ ®️ U+2328 ⌨ ⌨︎ ⌨️ U+25B6 ▶ ▶︎ ▶️ U+2603 ☃ ☃︎ ☃️ U+2620 ...