The <feSpecularLighting> SVG filter primitive lights a source graphic using the alpha channel as a bump map. The resulting image is an RGBA image based on the light color. The lighting calculation follows the standard specular component of the Phong lighting model. The resulting image depends on the light color, light position and surface geometry of the input bump map. The result of the lighting calculation is added. The filter primitive assumes that the viewer is at infinity in the z direction.

The <animate> SVG element provides a way to animate an attribute of an element over time.

The <feFuncB> SVG filter primitive defines the transfer function for the blue component of the input graphic of its parent <feComponentTransfer> element.

The crossorigin attribute, valid on the <image>, <feImage>, and <script> elements, provides support for configuration of Cross-Origin Resource Sharing (CORS) requests for the element's fetched data.

The await using declaration declares block-scoped local variables that are asynchronously disposed. Like const, variables declared with await using must be initialized and cannot be reassigned. The variable's value must be either null, undefined, or an object with a [Symbol.asyncDispose]() or [Symbol.dispose]() method. When the variable goes out of scope, the [Symbol.asyncDispose]() or [Symbol.dispose]() method of the object is called and awaited, to ensure that resources are freed.

A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.

A lookbehind assertion "looks behind": it attempts to match the previous input with the given pattern, but it does not consume any of the input — if the match is successful, the current position in the input stays the same. It matches each atom in its pattern in the reverse order.

The JavaScript exception "invalid property name in regular expression" or "invalid class property name in regular expression" occurs when the \p and \P Unicode character class escapes are not followed by a valid Unicode property name and/or value.

SVG supports the built-in XML xml:space attribute to handle whitespace characters inside elements. Child elements inside an element may also have an xml:space attribute that overrides the parent's one.

The y2 attribute is used to specify the second y-coordinate for drawing an SVG element that requires more than one coordinate. Elements that only need one coordinate use the y attribute instead.