The elevation attribute specifies the direction angle for the light source from the XY plane towards the Z-axis, in degrees. Note that the positive Z-axis points towards the viewer of the content.

A lookahead assertion "looks ahead": it attempts to match the subsequent 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.

The for statement creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement (usually a block statement) to be executed in the loop.

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

The division (/) operator produces the quotient of its operands where the left operand is the dividend and the right operand is the divisor.

The filter attribute specifies the filter effects defined by the <filter> element that shall be applied to its element.

The kernelUnitLength attribute has two meanings based on the context it's used in. For lighting filter primitives, it indicates the intended distance for the x and y coordinates, for <feConvolveMatrix>, it indicates the intended distance between successive columns and rows in the kernel matrix.

A buffer type used with `Read::read_vectored`.

Iteration protocols aren't new built-ins or syntax, but protocols. These protocols can be implemented by any object by following some conventions.

JavaScript's strict mode is a way to opt in to a restricted variant of JavaScript, thereby implicitly opting-out of "sloppy mode". Strict mode isn't just a subset: it intentionally has different semantics from normal code. Strict mode code and non-strict mode code can coexist, so scripts can opt into strict mode incrementally.