descriptor_item_name

descriptor_item_name 
      ::= 
      "type" 
      | "length" 
      | "octet_length" 
      | "returned_length" 
      | "returned_octet_length" 
      | "precision" 
      | "scale" 
      | "datetime_interval_code" 
      | "datetime_interval_precision" 
      | "nullable" 
      | "indicator" 
      | "data" 
      | "name" 
      | "unnamed" 
      | "collation_catalog" 
      | "collation_schema" 
      | "collation_name" 
      | "character_set_catalog" 
      | "character_set_schema" 
      | "character_set_name" 

This rule is called by

-> get_item_information
-> set_item_information