The <vkern> SVG element allows to fine-tweak the vertical distance between two glyphs in top-to-bottom fonts. This process is known as kerning.

The Promise() constructor creates Promise objects. It is primarily used to wrap callback-based APIs that do not already support promises.

A capturing group groups a subpattern, allowing you to apply a quantifier to the entire group or use disjunctions within it. It memorizes information about the subpattern match, so that you can refer back to it later with a backreference, or access the information through the match results.

A backreference refers to the submatch of a previous capturing group and matches the same text as that group. For named capturing groups, you may prefer to use the named backreference syntax.

The left shift assignment (<<=) operator performs left shift on the two operands and assigns the result to the left operand.

The marker-mid attribute defines the arrowhead or polymarker that will be drawn at all interior vertices of the given shape.

The display attribute lets you control the rendering of graphical or container elements.

The glyph-orientation-vertical attribute affects the amount that the current text position advances as each glyph is rendered.

The fr attribute defines the radius of the focal point for the radial gradient.

The exponentiation (**) operator returns the result of raising the first operand to the power of the second operand. It is equivalent to Math.pow(), except it also accepts BigInts as operands.