# Bad value X for the attribute “xmlns” (only “http://www.w3.org/2000/svg” permitted here). > Canonical HTML version: https://rocketvalidator.com/html-validation/bad-value-x-for-the-attribute-xmlns-only-http-www-w3-org-2000-svg-permitted-here > Attribution: Rocket Validator (https://rocketvalidator.com) > License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) On `` and the elements inside it, the `xmlns` attribute can only hold the SVG namespace, `http://www.w3.org/2000/svg`. When the HTML parser reads inline SVG, it places `` and its descendants in the SVG namespace by itself, whatever `xmlns` says. The main exception is content inside ``, which is parsed as HTML. Because the attribute can't change the namespace, the HTML standard makes any other value a parse error, whether it sits on the `` element or on a child such as `` or ``. A trailing slash or the XHTML namespace triggers it just like an unrelated URI does. Design tools are a common source. Adobe Illustrator can export a `` block holding an `` element declared in its own Save for Web namespace, `http://ns.adobe.com/SaveForWeb/1.0/`. In a standalone `.svg` file, which is parsed as XML, that declaration puts `` in Adobe's namespace. Pasted into HTML, the declaration has no effect and `` becomes an unknown SVG element, so the validator also reports `sfw` and `slices` as unknown elements. Browsers don't render ``, so deleting the block leaves the graphic unchanged, and SVG optimizers such as SVGO remove it by default. For the attribute itself, either set it to exactly `http://www.w3.org/2000/svg` or remove it, because inline SVG in HTML doesn't need it. ## Invalid example ```html ``` ## Valid example ```html ```