Fable 5.1 bans lyrics and characters as music publishers sue Anthropic

Fable 5.1's system prompt bans reproducing song lyrics, poems, and book passages in whole or in part, including line-by-line extraction, with an exemption for works published before 1929. The restrictions appeared within days of Sony Music Publishing and Warner Chappell suing Anthropic over training on song lyric databases, with coverage describing the timing as suggesting the changes are a response to that litigation. The prompt, confirmed at over 270,000 characters by a leaked post, also prohibits generating visual works depicting known characters, mascots, or logos through any medium Claude can produce, including SVG, HTML, and ASCII art, with Claude directed to judge requests by what the finished image would look like. Harm-reduction URLs for dancesafe.org, tripsit.me, and psychonautwiki.org are named for substance queries, the first instance of non-Anthropic URLs in any published Claude system prompt according to Willison. Style guidance bans the words 'genuinely,' 'honestly,' and 'straightforward.' Handling of abusive users shifted from an end_conversation tool trigger to guidance that Claude should maintain self-respect. The weapons-related paragraph was shortened compared to the July version.