Why are the ten questions: "whether", "what", etc. referred to in two ways:as questions, and as rules? Here is an excerpt adapted from Fr. Francisco Marçal's commentary on Ars Brevis, clarifying this important point.

"The Rules are considered in two ways, as they are called by two different terms, in this text and in many other writings. Namely, they are referred to both as principles, and as rules. Now we want to give you the reasons for this double appellation.
The first reason considers the topic: when the topic is doubtful or unknown to you, they are called questions. When the topic is known to you, and you use them to clarify it for someone who does not know, then they are called rules.
The second reason considers the role played by the user. When you use them to gain knowledge of something you do not know, they are questions. When you use them to respond to someone's question with what you know, they are rules.
The third reason refers to the mind: if you are using them to help your mind to resolve some doubt, they are questions. But they are rules when you apply your mind with them to compose reasons to better prove your point.
The fourth reason refers to the content of the questions and rules. As questions, they contain in their species,various questionnaires to be filled.. As rules, they contain various regulations to be implemented
The fifth reason refers to the Art: as parts of the material of the Art, they are called questions. But as fountainheads of new reasons, they are called rules.
This is how Canon Belver, a renowned Artist, who has brightened the glory of Maiorca as a seat of learning, freely interprets the matter in his Apology, or brief summary of the Rules of the Art.
And all these reasons stem from the one given by Blessed Raymond in his "Brief reading of the General Table", in its last part, in the chapter about the rules, as he says:
'In the beginning, we had said that the ten rules are ten general questions. And by this we must understand that they are called rules because they regulate the Artist's work in finding whatever he is looking for, in the truths and the natural secrets that are investigated with this Art, following these rules. But they are also called questions, because they are put in the form of questions, or interrogations.'
If you apply the species of the rule of "what" to this single reason given by Blessed Raymond, and to the five terms: "topic", "role", "mind", "content" and "Art", you will easily find the five reasons advanced by Belver."

Contents of Ars Infusa