Mark stricken text
del

The del element is used during editing and proofreading to signal the removal of old text from the author's original composition.
By convention deleted text is visually highlighted by the browser with strikethroughs.
Example
article {
h1 The Wobbly Lunar Orbit
Variations in the Moon's orbital speed due to its orbital
eccentricity cause a libration of several degrees of
longitude; the alignment of the Moon's orbital plane
causes a similar libration in latitude.
<<del Slightly more than half (about 59%) of the Moon's
surface can be seen from Earth due to libration.>>
}