SVG: When to use
xmlns attribute is required for SVG files
but optional for inlined SVGs.
version attribute is always optional.
Table of contents
xmlns:xlinkattributes are optional for inlined SVGs in HTML.
xmlnsattribute is required for SVG files and SVGs in CSS, e.g.:
xmlns:xlinkattribute is required for SVG files with
xlink:attributes. Similarly for SVGs in CSS.
version attribute is ignored and thus always optional.
Plus it's deprecated since SVG 2.