<s>
Content that is no longer accurate or relevant, struck through but kept visible.
Baseline: Widely available · Inline text semantics
When to use it
Old prices, sold-out notices, superseded facts that weren't formal 'edits'.
When not to
For tracked document edits use del; for decoration use CSS text-decoration.
Example
$49.00 now $29.00
<p><s>$49.00</s> now $29.00</p>