الْمَذْكُورُ
What can be mentioned or made an object of thought.
This wording is deliberately broad. Restricting the object of knowledge to something externally existent would make it hard to include true judgments about absence and impossibility. One may know that an object exists, but one may also know that a specified object is not present.
Example 1: “This book is on the table” concerns an existent object. Example 2: “There is no elephant in this room” concerns the absence of a particular kind of object. In neither case does the mere ability to speak about the subject prove that it exists externally. Mentionability and actuality must remain distinct.