The xlink:arcrole attribute specifies a contextual role for the element and corresponds to the RDF Primer notion of a property.

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.

The JavaScript exception "use of super property/member accesses only valid within methods or eval code within methods" occurs when the super.x or super[x] syntax is used outside of a method.

The JavaScript exception "setter functions must have one argument" occurs when a setter is declared and the parameter list is not consisted of exactly one formal parameter.

The JavaScript exception "class constructors must be invoked with 'new'" occurs when a class constructor is called without the new keyword. All class constructors must be called with new.

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 exception "TypeError: matchAll/replaceAll must be called with a global RegExp" occurs when the String.prototype.matchAll() or String.prototype.replaceAll() method is used with a RegExp object that does not have the global flag set.

The JavaScript strict mode-only exception "setting getter-only property" occurs when there is an attempt to set a new value to a property for which only a getter is specified, or when setting a private property that similarly only has a getter defined.

The JavaScript exception "missing : after property id" occurs when objects are created using the object initializer syntax. A colon (:) separates keys and values for the object's properties. Somehow, this colon is missing or misplaced.

The visibility attribute lets you control the visibility of graphical elements. With a value of hidden or collapse the current graphics element is invisible.