The Reference Manual is Book 3 of the ACUCOBOL-GT documentation set.
Chapter 1: "Introduction" gives an overview of the Reference Manual and includes information on the conventions used.
Chapter 2: "Program Structure" describes the overall structure of a COBOL program and provides basic information about the format of user-defined words, literals, and source code.
Chapter 3: "Identification Division" gives a detailed description of the COBOL Identification Division.
Chapter 4: "Environment Division" describes the COBOL Environment Division.
Chapter 5: "Data Division" describes the COBOL Data Division.
Chapter 6: "Procedure Division" describes the COBOL Procedure Division. This also contains a complete discussion of all the verbs used by ACUCOBOL-GT.