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tag creates a widget whose content becomes visible or invisible by the user toggling its visibilty (typically by clicking a triangle). <!doctype html> <html><body> The three main <a href='development/languages/Metasyntactic-variables'>metasyntactic variables</a>: <details> <ul style='margin-top:0'> <li>foo <li>bar <li>baz </ul> </details> More text … </body></html>
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