Re: [xdi] Second draft of simplified top-level ABNF

person-singleton     = "=" C-I ( xdi-name / xref / xdi-scheme )
legal-singleton      = "+" C-I ( xdi-name / xref / xdi-scheme )
general-singleton    = "*" C-I ( xdi-name / xref / xdi-scheme )
unreserved-class     = "#" C-I ( xdi-name / xref / xdi-scheme )