在翻譯航空手冊中，總會遇到很多的“WARNINGS”, "CAUTIONS" ,"NOTES" 和"Alert"，各種機型都有，曾經出現過多種說法，比如warning是警告，caution是警戒，note是注, alert是警報。由于各個公司已經形成了自己的慣用用法，所以這里只提出建議用法。

      在空客手冊中，是這樣定義的：DEFINITIONS OF WARNINGS, CAUTIONS AND NOTES
      The following are the official definitions of warnings, cautions and notes taken directly from the JAR25/CS-25 and applicable to Airbus flight operation documentation:
      WARNING：An operating procedure, technique, etc. that may result in personal injury or loss of life if not followed. 如果不遵守該語句可能會造成人員受傷或死亡，可見比較嚴重。
      CAUTION：An operating procedure, technique, etc. that may result in damage to equipment if not followed. 如果不遵守該語句，可能會造成設備損壞，程度低了。
      NOTE：An operating procedure, technique, etc. considered essential. 只是認為是重要的，做以強調。

      在波音手冊中，是這樣定義的：Warnings, Cautions, and Notes

      The following levels of advisories are used throughout the manual and are not to be confused with EICAS messages, which are separately identified in the text.
      WARNING: An operating procedure, technique, etc., that may result in personal injury or loss of life if not carefully followed.
      CAUTION: An operating procedure, technique, etc., that may result in damage to equipment if not carefully followed.
      Note: An operating procedure, technique, etc., considered essential to emphasize. Information contained in notes may also be safety related.

      可見關于這幾個詞的定義是差不多的

      在龐巴迪公務機手冊中，是這樣定義的：