The JavaScript exception "parameter after rest parameter" occurs when a rest parameter is followed by anything else in a parameter list, including another rest parameter, a formal parameter, or a trailing comma.

The JavaScript exception "invalid unicode escape in regular expression" occurs when the \c and \u character escapes are not followed by valid characters.

The <use> element takes nodes from within an SVG document, and duplicates them somewhere else. The effect is the same as if the nodes were deeply cloned into a non-exposed DOM, then pasted where the <use> element is, much like cloned <template> elements.

The dy attribute indicates a shift along the y-axis on the position of an element or its content.

An expression statement is an expression used in a place where a statement is expected. The expression is evaluated and its result is discarded — therefore, it makes sense only for expressions that have side effects, such as executing a function or updating a variable.

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

The JavaScript exception "missing : after property id" occurs when objects are created using the object initializer syntax. A colon (:) separates keys and values for the object's properties. Somehow, this colon is missing or misplaced.

The JavaScript strict mode-only exception "for-in loop head declarations may not have initializers" occurs when the head of a for...in contains an initializer expression, such as for (var i = 0 in obj). This is not allowed in for-in loops in strict mode. In addition, lexical declarations with initializers like for (const i = 0 in obj) are not allowed outside strict mode either.

The JavaScript exception "functions cannot be labelled" occurs when a function declaration has a label before it.

The baseFrequency attribute represents the base frequency parameter for the noise function of the <feTurbulence> filter primitive.