Ships of the Prussian and Imperial German names used SMS as a prefix. The Nazi and Post-WWII Navies used no prefix.
Ships of the Modern are named by pennet number which is sometimes followed by a name. The pennet number includes a letter and a 3 digit number. The Nazi's used a similar system for smaller craft while larger craft had just a name with no prefix or pennent number. Small craft may have only a pennet number and no name. Examples