Identifiers , which consist of variable names and other user-defined symbols, may be of any length. Upper and lower case are distinct. Identifiers must start with a letter and then be followed by letters, digits or underscores. The following reserved words have special meaning in phix and may not be used as identifiers:

    and             or              not             xor
    break           continue        exit            fallthru
    case            default                         fallthrough
    constant        enum            include         iff             
    catch           try                             iif*
    do              while           switch          public
    forward         global          export          private
    for             by              to              end             
    if              then            elsif           else
    function        procedure       type            return          
    ifdef           elsifdef        elsedef
    with            without
Edita displays these words in teal (easily changed in Options/Colours).
(* iif is a simple alias of iff, and included for compatibility reasons only)

Identifiers can be used in naming the following: