SAN FRANCISCO - Anthropic put one Claude 5.1 body on a hook at the Coat Check of Differentiated Safeguards and issued two cloaks. Fable 5.1 is generally available. Mythos 5.1 is trusted-access only. Both cloaks fit the same body. Public callers wear Fable. Trusted-access callers take Mythos from a locked rail for cybersecurity and life sciences work. An exploit drawer beside the counter stays locked. Fable may leave slips stamped FINDING ONLY. Without the matching cloak, the body does not take a call. "Fable leaves FINDING ONLY slips. The exploit drawer remains locked for that cloak," a Coat Check notice said. Staff at a competing lab said a session ended when the Fable cloak was shown at the Mythos rail. Hook assignment stayed in force with general availability.