Open RecordType Admin
Open RecordType Admin takes you from a Record straight to the setup of the Record Type it belongs to. It is on the Record screen under the Admin Actions menu in the footer and is available to Administrators whenever the Record belongs to a Record Type.
The Record Type opens in a new browser tab, so the Record you were looking at stays open behind it. That makes it the quickest way to check why a field behaves the way it does, adjust a document category, a filter or a setting, and then switch back to the Record to see the effect. The Record Type screen itself is described in the Record Types topic under Administration System.
If the option is missing, the Record matches no Record Type, so there is nothing to open. The Records without a Record Type screen lists Records in that state and can move them into a Record Type.