DITA For Publishers Vocabulary Reference linethrough linethrough specifies text that should appear as if struck out. It is often used to show corrections in explanatory or learning material. linethrough is a specialization of ph. Inheritance + topic/ph d4p-formatting-d/linethrough <p>The Greek letter <linethrough>rho</linethrough> pi represents the ratio of a circle's circumference to its diameter.</p>Figure 11. Sample of an instance of the linethrough element