Use 'cognizance' when an issue or subject is relevant to someone's interests or responsibilities. The engineer took cognizance of the new safety protocols.
Pro Tip 2/3
Unexpected Awareness
'Cognizance' implies gaining knowledge unexpectedly or coming to realize. She suddenly took cognizance of the fact that the deadline was today.
Pro Tip 3/3
Formal Expression
The term 'cognizance' is formal and more common in written English than spoken. Upon taking cognizance of the issue, the committee acted promptly.