1     Scope
 2     References
 3     Definitions
 4     Abbreviations
 5     Overview of this Recommendation
 6     Description of signals and messages
        6.1     Escape Signal (ES)
        6.2     Mode Request (MR)
        6.3     Capabilities Request (CR)
        6.4     Mode Select (MS)
        6.5     Capabilities List (CL)
        6.6     Capabilities List Request (CLR)
        6.7     Acknowledge Message (ACK)
        6.8     Negative Acknowledge Message (NAK)
 7     Structure of signals and messages
        7.1     Signals
                  7.1.1     Frequencies
                  7.1.2     Duration
                  7.1.3     Tolerances
                  7.1.4     Transmitted power levels
        7.2     Messages
                  7.2.1     Transmitted power level
                  7.2.2     Format convention
                  7.2.3     Frame structure
                  7.2.4     Preamble
                  7.2.5     Flag sequence
                  7.2.6     Information field
                  7.2.7     Frame check sequence field
                  7.2.8     Transparency
                  7.2.9     Invalid frames
 8     Information field coding format
        8.1     General
        8.2     Coding format for parameters in the I and S fields
                  8.2.1     Parameter classification
                  8.2.2     Order of transmission of parameters
                  8.2.3     Delimiting and parsing of data blocks
        8.3     Identification field (I)
                  8.3.1     Message type
                  8.3.2     Revision number
                  8.3.3     Parameter field
        8.4     Standard information field (S)
                  8.4.1     ACK and NAK messages
                  8.4.2     MS, CL, and CLR messages
        8.5     Non-standard information field (NS)
        8.6     Information field length
 9     V.8 bis transactions
        9.1     Permitted V.8 bis transactions
        9.2     Transactions permitted at any time on the PSTN and on leased point-to-point circuits
                  9.2.1     Transactions with no a priori knowledge of V.8 bis support
                  9.2.2     Transactions with a priori knowledge of V.8 bis capability
        9.3     Transactions permitted only upon automatic answering of a PSTN call
        9.4     Use of escape signals
        9.5     Use of the Negative Acknowledge Message (NAK)
        9.6     State transition diagrams
        9.7     Suppression of ACK(1) after an MS message
        9.8     Error recovery
        9.9     Procedures for initiating a modem start-up after a V.8 bis transaction
                  9.9.1     V.8 start-up following a V.8 bis transaction
                  9.9.2     Shortened V.8 start-up following a V.8 bis transaction
                  9.9.3     V.25 start-up following a V.8 bis transaction
       9.10     Message segmentation
10     Operating procedures
       10.1     Operating procedures when not automatically answering on the PSTN and on leased point-to-point circuits
                 10.1.1     Initiating station (MR or CR initiation)
                 10.1.2     Initiating station (MS, CL or CLR)
                 10.1.3     Responding station
       10.2     Operating procedures upon automatic answering of a call on the PSTN
                 10.2.1     Calling station
                 10.2.2     Answering station (MRe or CRe initiation)
                 10.2.3     Answering station (MS, CL or CLR initiation)
11     DTE-DCE interface
Appendix I - Recommendation V.8 bis features
        I.1     Introduction
        I.2     Basic features of this Recommendation
        I.3     Selection of a desired communication mode
        I.4     Identification of common operating modes
        I.5     Automatic selection between terminals
        I.6     User-friendly switching from telephony to data
        I.7     Conferencing applications
        I.8     Interworking considerations
        I.9     Relationship between ITU-T V.8 and V.8 bis
Appendix II - Examples of V.8 bis transactions
Appendix III - Effect of echo suppressors
      III.1     Introduction
      III.2     Operation of echo suppressors
      III.3     Dual tone signal breakthrough of echo suppressors
      III.4     V.8 bis transactions 4, 5 and 6
      III.5     Automatic answering together with a voice recording device
                III.5.1     Blocking of V.8 bis initiating signals
                III.5.2     Blocking of response to MRe and CRe by OGM
      III.6     Optional status of provisions