<textual-form>
Textual Form
This element holds text (mixed content) in places where alternatives can be
presented, providing a textual alternative. For example, inside the <alternatives> wrapper element, a <textual-form> can provide an alternative version of an equation, graphic, or table. This
alternative textual version may be a direct textual representation of an object (such as a Unicode
value for a special character or the full text of an equation in ASCII characters), or a simplified textual version of the object (for display by devices not able to cope with the object), or a text-dump of the contents of a binary object (for example, the full text-dump of the cells of a table to accompany a graphic version of the table).