Unicode Variation Selector-15 and some of my tears

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 posts1 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,…