Editing Sub-lieutenant (section)

=== Acting sub-lieutenant ===
In 1955, the Royal Navy created the rank of [[Acting (rank)|acting]] sub-lieutenant, although it had existed intermittently in the world wars. Unlike their substantive counterparts, acting sub-lieutenants are [[subordinate officer]]s, as they hold their ranks by order and not by commission. Upon passing [[fleet board]], acting sub-lieutenants were confirmed as sub-lieutenants and issued commissions backdated to the date when they were appointed acting sub-lieutenants. The rank of acting sub-lieutenant was abolished in the Royal Navy around 1993 but remained in the [[Royal Naval Reserve]] until 2013; officers in both the RN and RNR now commission into the rank of [[midshipman]].<ref name=RNBR3Ch102>{{cite web |title=BR3, Ch102 – Maritime Reserves Personnel Management |url=http://www.royalnavy.mod.uk/~/media/royal%20navy%20responsive/documents/reference%20library/br%203/br3book/ch102.pdf |website=Royal Navy Books of Reference |publisher=[[Royal Navy]] |access-date=31 December 2015 |archive-url=https://web.archive.org/web/20160304094007/http://www.royalnavy.mod.uk/~/media/royal%20navy%20responsive/documents/reference%20library/br%203/br3book/ch102.pdf |archive-date=4 March 2016 |url-status=live}}</ref> The rank of acting sub-lieutenant remains in the Royal Navy only within the [[University Royal Naval Unit]] where training officers enter at this rank.<ref name=RNBR3Ch110>{{cite web |title=BR3, Ch 110 – The University Royal Naval Units and Cadet Forces |url=http://www.royalnavy.mod.uk/~/media/royal%20navy%20responsive/documents/reference%20library/br%203/br3book/ch110.pdf|website=Royal Navy Books of Reference |publisher=[[Royal Navy]] |access-date=31 December 2015 |archive-url=https://web.archive.org/web/20150824011951/http://www.royalnavy.mod.uk/~/media/royal%20navy%20responsive/documents/reference%20library/br%203/br3book/ch110.pdf |archive-date=24 August 2015 |url-status=live}}</ref>

Before its abolition, the rank of acting sub-lieutenant in the Royal Navy corresponded with, but was junior to, the ranks of lieutenant (Army) and flying officer (RAF).

In many Commonwealth navies (e.g. Canada and Australia), the rank of acting sub-lieutenant still exists as a commissioned rank equivalent to second lieutenant, while the rank of sub-lieutenant is equivalent to that of an army lieutenant. As the term "[[Acting (rank)|acting]]" is a designation, both acting and substantive ranks should be addressed as "sub-lieutenant"; the full designation including "acting" should be used in written documents, however. Indeed, when someone is addressed as "acting sub-lieutenant", it can be seen as a way of patronising an individual in a derogatory manner due to the emphasis of their "acting" rank.

The [[Royal New Zealand Navy]], [[Republic of Fiji Navy]] and [[South African Navy]] follows the US precedent in titling its lowest commissioned officer [[Ensign (rank)|ensign]].

In the [[Royal Thai Army]], [[Army Reserve Force Students]] who complete grade 5 and their B.D. are promoted to the rank of acting second lieutenant (ว่าที่ ร้อยตรี).