The in2 attribute identifies the second input for the given filter primitive. It works exactly like the in attribute.

The gradientTransform attribute contains the definition of an optional additional transformation from the gradient coordinate system onto the target coordinate system (i.e., userSpaceOnUse or objectBoundingBox). This allows for things such as skewing the gradient. This additional transformation matrix is post-multiplied to (i.e., inserted to the right of) any previously defined transformations, including the implicit transformation necessary to convert from object bounding box units to user space.

The markerUnits attribute defines the coordinate system for the markerWidth and markerHeight attributes and the contents of the <marker>.

The id attribute assigns a unique name to an element.

The mask attribute is a presentation attribute mainly used to bind a given <mask> element with the element the attribute belongs to.

The JavaScript exception "radix must be an integer at least 2 and no greater than 36" occurs when the optional radix parameter of the Number.prototype.toString() or the BigInt.prototype.toString() method was specified and is not between 2 and 36.

The k1 attribute defines one of the values to be used within the arithmetic operation of the <feComposite> filter primitive.

An input boundary assertion checks if the current position in the string is an input boundary. An input boundary is the start or end of the string; or, if the m flag is set, the start or end of a line.

The JavaScript exception "invalid decimal escape in regular expression" occurs when a legacy octal escape sequence is used in a Unicode-aware regular expression pattern.

The kernelMatrix attribute defines the list of numbers that make up the kernel matrix for the <feConvolveMatrix> element.