Concerns safety matters of secondary importance or which are not immediately imminent.

      CONCERNS SAFETY MATTERS OF PRIMARY IMPORTANCE OR WHICH ARE IMMEDIATELY IMMINENT.

      在湾流手册中，是这样定义的：Warnings, Cautions and Notes: Used throughout this manual, these adjuncts highlight and emphasize certain points, and are not to be confused with Engine Instruments and Crew Alerting System (EICAS) messages. Shown below, each is explained in the style it will appear in this manual:

      CALLS ATTENTION TO THE USE OF MATERIALS, PROCESSES, METHODS, PROCEDURES OR LIMITS WHICH MUST BE PRECISELY FOLLOWED TO AVOID PERSONAL INJURY OR LOSS OF LIFE.

      CALLS ATTENTION TO THE USE OF MATERIALS, PROCESSES, METHODS, PROCEDURES OR LIMITS WHICH MUST BE PRECISELY FOLLOWED TO AVOID DAMAGE TO EQUIPMENT.

      Calls attention to methods or information essential to emphasize, usually to make a procedure easier.