Pre-nominal letters

Pre-nominal letters are a title which is placed "before" the name of a person as distinct from a post-nominal title which is placed "after" the name. Examples of pre-nominal titles, for instance professional titles include: Doctor, Captain, Eur Ing (European Engineer), Ir (Ingenieur), CA (Indian Chartered Accountant) and Professor; whilst other common social titles are Mr., Master, The Honorable, Ms., Mrs. and Miss. Pre-nominal letters are generally social, but can be professional in nature (e.g. Eur Ing).
Academic degrees.
In some Continental European countries all academic degrees were traditionally pre-nominal.
Pre-nominal academic degrees in German-speaking countries include: "Dipl.-Ing." (Master's degree in Engineering), "Dipl.-Kfm." (master's degree in management), "Dipl.-Phys." (master's degree in physics), "Dr.-Ing." (German doctorate in engineering), "Dr. med." (German doctorate in Medicine) and "Mag." (Austrian master's degree (Magister) in all disciplines except engineering).
Pursuant to the Bologna process, most of these pre-nominal degrees will be replaced by post-nominal bachelor's and master's degrees; but people who held academic degrees before the Bologna process may continue to use the pre-nominal academic degrees. In contexts where pre-nominal academic letters are used, such degrees may be placed prenominally for consistency (for example, "MMathPhil Marcos Cramer").
In Finland, abbreviated academic titles can appear before or after the name (for example, FM Matti Meikäläinen or Matti Meikäläinen, FM). In the United States a person may at their discretion use "Dr." as a pre-nominal or their doctoral degree's initials as a post-nominal, but rarely at the same time. It would also be very unusual to see a professional license (such as for an engineer) used as a pre-nominal in any form. 
In Poland, abbreviated academic titles appear as pre-nominal letters: "inz." for holders of inżynier degree (Polish equivalent for a Bachelor of Science (BSc), Bachelor of Engineering (BEng), or Bachelor of Applied Science (BASc)) awarded by a polytechnical university or faculty; "mgr" for holders of a Magister (Polish equivalent for a master's degree); "mgr inz." for holders of a Magister awarded by a polytechnical university or faculty; "dr" for holders of a Doktorat (Polish Doctorate); "dr inz." for holders of a Doktorat awarded by a polytechnical university or faculty; "dr hab." for holders of a Doktorat and a habilitacja (Polish post-doctoral habilitation qualification); "dr hab. inz." for holders of a Doktorat and a habilitacja awarded by a polytechnical university or faculty.
In Portugal and the other Portuguese-speaking countries, it is usual for a person with a university degree to be generally referred by the abbreviated pre-nominal title "dr." ("doutor"), independently of the real degree that he or she holds. The main exceptions to this are the holders of degrees in engineering and architecture, who are referred respectively by the pre-nominal abbreviated titles "eng." ("engenheiro") and "arq." ("arquiteto").
Order of titles.
In the UK, those with both a knighthood and rank in the armed forces (or clergy, or academic titles) put the "Sir" after the other title; for example: Lieutenant General Sir William Leishman; His Eminence Sir Norman Cardinal Gilroy, KBE; Professor Sir Richard Peto.