That legal notice presumed to exist when a person is in command of sufficient facts as would cause a reasonable person to make further inquiries.
Example: If one buys real property and knows that it is occupied by someone other than the seller, then the buyer has an obligation to make inquiries to find out the character of the rights of the occupant, whether the occupant has a long-term lease, no lease at all, or is claiming title to the property as his or her own. But, having failed to make any inquiry, the purchaser cannot make a claim against the seller if the occupant claims rights in the property.