WaterML2.0 defines a generic collection feature type, Collection, to allow the grouping of observations and/or sampling features with metadata to describe the nature of the collection. Such collections are required in a number of data exchange scenarios; whether the underlying transport technology is web services, FTP or other technologies. 
    
 
            
    
    
        
                
                    
                        | Egenskap | Stereotype | Beskrivelse | Type | Multiplisitet | 
                
                    
                        | communityExtension |  |  | Any | 0..* | 
                    
                        | internalExtension |  |  | Any | 0..* | 
                    
                        | localDictionary |  |  | Dictionary | 0..* | 
                    
                        | temporalExtent |  | Describes the temporal extent of the all the time series contained within the collection (if they exist). | TM_Period | 0..1 | 
                    
                        | parameter |  | A soft typed parameter for extra metadata properties. | NamedValue | 0..1 | 
        
     
    
        
                
                    
                        | Navn | Type | Lengde | Multiplisitet | 
                
                    
                        |  | Any |  | 0..* | 
                    
                        |  | Any |  | 0..* | 
                    
                        |  | Dictionary |  | 0..* | 
                    
                        |  | TM_Period |  | 0..1 | 
                    
                        |  | NamedValue |  | 0..1 |