Germany’s law on security clearance states the rule in one sentence. Von einer Verschlusssache dürfen nur Personen Kenntnis erhalten, die auf Grund ihrer Aufgabenerfüllung Kenntnis haben müssen. “Only persons who must know of a classified matter in order to do their task may learn of it.” The next sentence goes further. No person may be told more fully, or earlier, than the task requires. The federal administrative rules on classified information sum this up as Kenntnis nur, wenn nötig, knowledge only when necessary. The rule also covers the lowest grade, VS – Nur für den Dienstgebrauch, for official use only.