In the forum's that I've joined which support such tags, using [spoiler] text [/spoiler] yields a hidden field with a "Show" button next to the field. When the user clicks on the "Show" button, the hidden text is then revealed. Jokes would have more of an impact if the punchline was hidden (It may remove the temptation of skipping over the text of a long joke in order to reach the punchline). Thanks.
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