The limitingConeAngle attribute represents the angle in degrees between the spot light axis (i.e. the axis between the light source and the point to which it is pointing at) and the spot light cone. So it defines a limiting cone which restricts the region where the light is projected. No light is projected outside the cone.

The stitchTiles attribute defines how the Perlin Noise tiles behave at the border.

The JavaScript warning "test for equality (==) mistyped as assignment (=)?" occurs when there was an assignment (=) when you would normally expect a test for equality (==).

The stroke-opacity attribute is a presentation attribute defining the opacity of the paint server (color, gradient, pattern, etc.) applied to the stroke of a shape.

The JavaScript exception "await is only valid in async functions, async generators and modules" occurs when an await expression is used outside of async functions or modules or other async contexts.

The to attribute indicates the final value of the attribute that will be modified during the animation.

The JavaScript exception "invalid 'instanceof' operand" occurs when the right-hand side operands of the instanceof operator isn't used with a constructor object, i.e. an object which has a prototype property and is callable.

The JavaScript exception "called on incompatible target (or object)" occurs when a function (on a given object), is called with a this not corresponding to the type expected by the function.

A character class matches any character in or not in a custom set of characters. When the v flag is enabled, it can also be used to match finite-length strings.

The JavaScript exception "missing } after property list" occurs when there is a mistake in the object initializer syntax somewhere. Might be in fact a missing curly bracket, but could also be a missing comma.