Anthropic documents a prompt tweak that makes Claude Fable 5.2 consolidate duplicated code

Anthropic's documentation for Claude Fable 5.2 says the model pays close attention to who owns the code it works on. In testing on small coding tasks, the model consolidated duplicated code in under 10 percent of runs when the prompt said nothing about ownership, and in about 75 percent of runs when the prompt stated that the codebase was the model's own. The suggested sentence reads: You are the owner and long-term maintainer of this codebase, and its design is up to you.