The fetchpriority attribute provides a hint to the browser about the relative priority to use when fetching an external resource. This works the same way as the fetchpriority attribute for the HTML <img> and <script> elements.

The diffuseConstant attribute represents the kd value in the Phong lighting model. In SVG, this can be any non-negative number.

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.

The fill attribute has two different meanings. For shapes and text it's a presentation attribute that defines the color (or any SVG paint servers like gradients or patterns) used to paint the element; for animation it defines the final state of the animation.

The JavaScript exception "missing ) after condition" occurs when there is an error with how an if condition is written. It must appear in parenthesis after the if keyword.

The <feImage> SVG filter primitive fetches image data from an external source and provides the pixel data as output (meaning if the external source is an SVG image, it is rasterized.)

The comma (,) operator evaluates each of its operands (from left to right) and returns the value of the last operand. This is commonly used to provide multiple updaters to a for loop's afterthought.

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.

The font-weight attribute refers to the boldness or lightness of the glyphs used to render the text, relative to other fonts in the same font family.