anchor.diff:                   | ALPHA ( (ALPHA | DIGIT ) | DASH )* (ALPHA | DIGIT )
                    ;
           
  -parameter: ';' pName=( ALPHA | DIGIT | DASH )+ ('=' pValue=(ParamUnreserved | SPECIAL | ALPHA | DIGIT | Mark | DASH | PctEncoded)+ )?;
  -               
  +parameter: ';' pName=( ALPHA | DIGIT | DASH )+ ('=' pValue=(ParamUnreserved | SPECIAL | ALPHA | DIGIT | Mark | STAR | VisualSeparator | DASH | PctEncoded)+ )?;
  +
   Mark: '_' 
  -    | '.' 
       | '!' 
       | '~' 
  -    | '*' 
       | '\'' 
  -    | '(' 
  -    | ')'
       ;
   
   PctEncoded: '%' HEX_DIGIT HEX_DIGIT;
              
   ParamUnreserved: '[' 
                  | ']' 
  -                        ;
  -               
  -PhoneDigit: DIGIT 
  -          | VisualSeparator
  -          ;
  +               ;
   
   fragment PhoneDigitHex: HEX_DIGIT 
  -                      | STAR_POUND
  +                      | STAR
  +                      | POUND
                         | VisualSeparator
  +                      | DASH
                         ;
   
  -fragment STAR_POUND: '*'
  -                   | '#'
  -                   ;
   
  -fragment VisualSeparator: DASH
  -                        | '.' 
  +
  +VisualSeparator: '.' 
                           | '(' 
                           | ')'
                           ;
  
positive.code:             
  localNumber: localDigits=LocalNumberDigits (extension | isdnSubaddress)? phoneContext parameter*;
  
  isdnSubaddress: ';isub=' isub=(Reserved | SPECIAL | ALPHA | DIGIT | Mark | DASH | PctEncoded)+;
  
  extension: ';ext=' ext=PhoneDigit+;
  
  phoneContext: ';phone-context=' pContext=(DomainName | GlobalNumberDigits);
  
  GlobalNumberDigits: '+' PhoneDigit* DIGIT PhoneDigit*;
                      
  LocalNumberDigits: PhoneDigitHex* (HEX_DIGIT | STAR_POUND) PhoneDigitHex*;         
            
  DomainName: ( DomainLabel '.' )* TopLabel ( '.' )?;
            
  
negative.code:         | ','
          ;
  
  STAR: '*';
  POUND: '#';
  
  SPECIAL: '+'
         | '$'
         | '&'
  