The decodeURI() function decodes a Uniform Resource Identifier (URI) previously created by encodeURI() or a similar routine.

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

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

The clipPathUnits attribute indicates which coordinate system to use for the contents of the <clipPath> element.

The Uint8Array typed array represents an array of 8-bit unsigned integers. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).

A view is a defined way to view the image, like a zoom level or a detail view.

The switch statement evaluates an expression, matching the expression's value against a series of case clauses, and executes statements after the first case clause with a matching value, until a break statement is encountered. The default clause of a switch statement will be jumped to if no case matches the expression's value.

The void operator evaluates the given expression and then returns undefined.

A character escape represents a character that may not be able to be conveniently represented in its literal form.

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.