"<desc>"

Provides an extended, human-readable description of its parent element or of the document as a whole.

The <desc> element and its contents are never rendered as part of the graphic.

• DOM object: SVGDescElement
• SVG2 spec: https://www.w3.org/TR/SVG2/struct.html#DescElement

<desc> is a descriptive element. Where "<title>" supplies a short accessible name, <desc> supplies a longer description that assistive technology can present to users who need more context than the title alone provides. Only the first <desc> child of an element is meaningful.

<svg width="100" height="100">
  <circle cx="50" cy="50" r="40">
    <title>Status indicator</title>
    <desc>A solid blue circle indicating the service is online.</desc>
  </circle>
</svg>

The text is available programmatically via SVGDescElement::textContent. Because the element is non-rendered, placing a <desc> inside a shape (or anywhere else) never changes the rendered pixels.