Certificate of sanity
From Jenny Everywhere Wiki
Collecting a certificate of sanity from the non-mad-science corner of the Lab, and then showing that certificate to the personification of February so as to gain entry in the hallway to nowhere, was one of the steps in the complex ritual needed to gain access to the Vault of the Strange and Wonderful House. This was carried out on at least one occasion by Frank the Janitor. (PROSE: Our Strange and Wonderful House: The Vault)
