Commander and Lieutenant Commander
These ranks should not be abbreviated.
How to Address a Commander or Lieutenant-Commander
The recommended style of address is as follows:
|Beginning of letter||Dear Commander/Lieutenant-Commander Jones|
|End of letter||Yours sincerely|
|Envelope||Commander John Smith, CBE, Royal Navy; Lieutenant Commander James Jones, Royal Navy|
|Verbal communication||Commander Smith*/Lieutenant Commander Smith|
|Invitation||Commander John Smith/Lieutenant Commander James Jones|
|Description in conversation||Commander Smith/Lieutenant Commander Jones|
|List of Directors or Patrons||Commander John Smith; Lieutenant Commander James Jones|
|Place card||Commander John Smith/Commander James Jones|
*A younger man, or a more junior officer in any of the Armed Forces, addresses him as 'Sir'.