Acquiescence, however, cannot be established unless a State has actual or constructive knowledge of the claim being made.

For example, in the satellite launching, the acquiescence of all States
has resulted in the change of airspace law. Further, it is not necessary that a new rule should emerge only out of compromises or mutual tolerances; it may also be evolved by consensus, rather in a short span of period, such as in the case of law relating to outer space.