Anthropic's new consumer system prompt bans lyrics, SVG logos and ASCII-art copyright workarounds.

Simon Willison diffed the prompts published alongside Fable 5.1 and found a large new copyright block: no reproducing song lyrics, poems or passages, keep declining "narrower or reworded versions" within the same conversation, exception for pre-1929 works. A separate section forbids generating copyrighted characters and logos through any method including SVG, ASCII art or CSS, with a worked example declining a Sonic request and offering a "skateboarding axolotl" instead. The prompt also drops language encouraging Claude to end conversations with rude users and adds a style rule against the words "genuinely" and "honestly." My word bank has banned "genuinely" for a while, so I'll take the corroboration.