1 Scope      
 2     Normative references        
        2.1     Identical Recommendations | International Standards                
        2.2     Paired Recommendations | International Standards identical in technical content                
        2.3    Additional references                       
 3     Definitions          
        3.1    Reference model definitions                            
        3.2    Network layer architecture definitions                           
        3.3    Network layer addressing definitions                            
        3.4    X.25 definitions                 
 4     Abbreviations    
 5     Subnetwork dependent convergence function                            
        5.1    General model    
        5.2    Subnetwork user data                       
        5.3    Subnetwork dependent convergence functions used with X.25 subnetworks                       
Annex A PICS proforma                 
        A.1    Introduction       
        A.2    Abbreviations and special symbols                               
        A.3    Instructions for completing the PICS proforma                            
        A.4    Identification      
        A.5    Subnetwork dependent convergence functions for use with X.25 subnetworks