Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as xml.
A tag starting with <? has been found within the document, but it’s not supported. Probable causes can be:
- Copy-pasting the contents of an SVG file. If you do that, you should only paste the <svg>...</svg> part, but not the first line with <?xml...>.
- Unprocessed <?...> tags on server scripting languages like PHP, like <?php>
- [freeCodeCamp: How to Use SVG Images in CSS and HTML]https://www.freecodecamp.org/news/use-svg-images-in-css-html/)
25,000 HTML checks per month. Fully automated.