SDL-92 is introduced in the paper, thereby concentrating on its advanc
ed aspects. This especially refers to features of the language not ava
ilable in SDL-88, the previous version of SDL. The paper shows how SDL
deals with abstraction and the use of types within the newly introduc
ed concepts of object-orientation. Other new features dealt with are r
emote procedures and nondeterminism. An incomplete example illustrates
how a system may be specified, thereby making use of a number of the
new concepts. Various hierarchical levels, such as system, block, proc
ess, procedure and service are covered. Some differences to SDL-88 are
listed and the reader is given some advice on further reading and edu
cation.