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.

The x attribute defines an x-axis coordinate in the user coordinate system.

The tabindex attribute allows you to control whether an element is focusable and to define the relative order of the element for the purposes of sequential focus navigation.

The u2 attribute specifies list of Unicode characters (refer to the description of the unicode attribute of the <glyph> element for a description of how to express individual Unicode characters) and/or ranges of Unicode characters, which identify a set of possible second glyph in a kerning pair.

The JavaScript Guide shows you how to use JavaScript and gives an overview of the language. If you need exhaustive information about a language feature, have a look at the JavaScript reference.

A named backreference refers to the submatch of a previous named capturing group and matches the same text as that group. For unnamed capturing groups, you need to use the normal backreference syntax.

The height attribute defines the vertical length of an element in the user coordinate system.

The dominant-baseline attribute specifies the dominant baseline, which is the baseline used to align the box's text and inline-level contents. It also indicates the default alignment baseline of any boxes participating in baseline alignment in the box's alignment context.

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

The right shift assignment (>>=) operator performs right shift on the two operands and assigns the result to the left operand.