The descent attribute defines the maximum unaccented depth of the font.

The id attribute assigns a unique name to an element.

The pointsAtY attribute represents the y location in the coordinate system established by attribute primitiveUnits on the <filter> element of the point at which the light source is pointing.

The panose-1 attribute indicates the Panose-1 number of a font face.

The nullish coalescing assignment (??=) operator, also known as the logical nullish assignment operator, only evaluates the right operand and assigns to the left if the left operand is nullish (null or undefined).

The color-interpolation attribute specifies the color space for gradient interpolations, color animations, and alpha compositing.

The addition (+) operator produces the sum of numeric operands or string concatenation.

The encodeURIComponent() function encodes a URI by replacing each instance of certain characters by one, two, three, or four escape sequences representing the UTF-8 encoding of the character (will only be four escape sequences for characters composed of two surrogate characters). Compared to encodeURI(), this function encodes more characters, including those that are part of the URI syntax.

The arabic-form attribute indicates which of the four possible forms an Arabic glyph represents.

The <feFlood> SVG filter primitive fills the filter subregion with the color and opacity defined by flood-color and flood-opacity.