The Categories of Legitimate Reservation (CLR) are the rules for scrutinizing the validity and logical soundness of thinking processes logic diagrams.

Seven logical reservations are grouped into three levels:

• Level I: Clarity Reservation. It seeks clarity and understanding of the tree builder‘s intentions, that is, finding out what the words and phrases in the logic diagram‘s entities really mean and how they are being used.
• Level II: causality existence and entity existence reservations. They examine the validity of an entity: asking whether the entity really exists; and whether the causal relationship between specified entities really exists.
• Level III: cause insufficiency, additional cause, predicted effect existence, cause-effect reversal or tautology reservations.

The scrutinizer must actively assist the presenter by proposing a change such as adding or changing some words and/or suggesting a missing condition or an entity that appears to be omitted. Scrutinizers should proceed from Level I to Level II to Level III reservations until they have satisfied their concerns.

That is, they should first seek clarity, next ensure causality and entity existence, and finally, propose improvements in the logic. Note that the tree builder is free to accept or reject any reservation at any level.