character_expression ::= { character_constant_name | character_function_call | character_literal | character_variable_name | :host_variable_name [:indicator_name] } [|| { character_constant_name | character_function_call | character_literal | character_variable_name | : host_variable_name [:indicator_name] } [|| { character_constant_name | character_function_call | character_literal | character_variable_name | : host_variable_name [:indicator_name] } ]...