relating to the supra-regional German used in the written language
There are many regional variations and dialects in Germany, Austria, and Switzerland. Hochdeutsch is the standard German that can be understood by all German speakers. It is probably the only way for a Bavarian, Austrian or Swiss to communicate with a North German. Newspapers and other publications are generally printed in Hochdeutsch, which is regarded as ‘proper’ German.
The standards and rules of Hochdeutsch are fixed in dictionaries and grammars.