Regelbeispiel is actually a term predominantly used in criminal law where it is used to determine the measure of a penalty ("Regelbeispiele sind benannte besonders schwere Fälle, die zur gesetzlichen Vermutung eines besonders schweren Falles führen" Creifelds, Rechtswörterbuch), meaning that if the legal elements of an offence (Tatbestand) are present, it will be presumed that this offence has been committed. Therefore, Regelbeispiele fulfill two roles: they are legal elements of an offence and they determine the measure of punishment.

Anyway, without getting to much into the nitty gritty of criminal law, this term is evidently also used in other areas, i.e tax law, where its seems to describe the definitional elements [constituent facts / operative facts] of a legal provision that will lead to a specific legal consequence.

Example: Definitional element "Rendite nach Steuern doppelt so hoch wie nach Steuern?" - Yes/No - then ... (ensuing legal consequence).

Now, these Regelbeispiele are all variations on the Grundtatbestand, i.e. the "basic facts of a case" or "basic legal elements that lead to a specific legal consequence".

I hope I haven't confused you too much with my excursion into criminal law, but I feel this was necessary to explain the background.