Jaguar XJS Do Not Slam (Bonnet decal)
 
Fitted to all but the final year of the facelift models and shows the correct way to gently close the bonnet and lock it down.  
 
This is a reproduction of the original decal.  The original is still available from Jaguar...a little bit more expensive but it is a original part. 
 https://parts.jaguarlandroverclassic.com/bec17641-under-bonnet-closing-label.html