New Claude prompt refuses lyrics and Sonic banners

Anthropic published the system prompts for its consumer Claude apps on September 2, and the new Fable 5.1 text tells Claude to refuse song lyrics, poems and book passages “in whole or in part”. Works first published before 1929 are fine, and Claude declines when it’s unsure of the date.

The same section covers art drawn with code: SVG, canvas, ASCII. One example has Claude declining a blue hedgehog birthday banner as Sonic and offering a skateboarding axolotl instead.

The lyrics rules landed days after Sony Music Publishing and Warner Chappell sued Anthropic over training on lyrics databases.

Anthropic’s docs return Markdown for any page if you add .md to the URL, which makes revisions easy to diff. The published core prompt leaves out feature blocks like the end_conversation rules.