data-*

The data-* SVG attributes are called custom data attributes. They let SVG markup and its resulting DOM share information that standard attributes can't, usually for scripting purposes. Their custom data are available via the SVGElement interface of the element the attributes belong to, with the SVGElement.dataset property.

The * can be replaced by any characters allowed in XML's rules for names, with the following restrictions:

Can't start with xml.
No semicolons (;, U+003A).
No capital A to Z letters.

Note: The SVGElement.dataset property is a DOMStringMap that provides the attribute data-test-value via SVGElement.dataset.testValue. Hyphen characters (-, U+002D) are removed and the next letter is capitalized, resulting in the camel case format.

You can use this attribute with any SVG element.