WordPress.org

The Rot13 Encoder/Decoder plugin allows bloggers and commenters to "encrypt" parts of their writing output with the ROT13 cipher in order to conceal media-related spoilers, punchlines, solutions, or sensitive topics from other readers who don't wish to read them.

• Allow readers to decode by single- or double-clicking the ROT13'd text
• Decodes either inline or a tooltip-style popup.

A TinyMCE button is included to help bloggers select text in their posts to ROT13. Commenters can use a BBCode-style tag (i.e., WordPress shortcode) in their comments: e.g. [rot13]Spoilerific content example[/rot13]