One of the difficulties in handling RSS feeds is that no one has ever defined what is allowed in the embedded HTML and what isn't. You clearly can't use all HTML elements. So readers have to define their own subset, filter what they don't support, and hope the feeds still render ok. Publishers have a similar problem. Should they expect the lowest common denominator, or can they use more style and structure? Many publishers just dump whatever they have on their website, and I'd like to shout to them, "There is no way this mess can look good in a reader", but I really can't, because the RSS spec allows them to do what they do. It's my problem if I filter out all their CSS. So I tried to find a solution, or at least the beginning of a solution, by defining an HTML subset that can safely be used in feed readers. This is what I determined for my own reader Downread as what's pretty much the maximum of what can work when safely embedding HTML in a webpage. Additionally, it also documents which exceptions are needed for YouTube, Vimeo, X, JW, Simplecast, Captivate, TikTok, Instagram, Threads, Reddit, and Bluesky embeds. So here is the document: https://github.com/bigwide-net/RFCs/blob/main/RFC-2-HTML-Subset-for-Feed-Content.md All comments welcome! Is something missing? Are there technical reasons against some of the features listed here? I would also be interested in cooperating with other authors of RSS consumers to have a common standard supported by more than a single reader.   submitted by   /u/Odd-Anteater875   to   r/rss [link]   [comments]