404. Usual form of covenant.

An express covenant for quiet enjoyment may be a qualified covenant (namely, a covenant that the tenant is peaceably to hold and enjoy the demised premises during the term1 without interruption by the landlord or persons claiming through or under him); or it may be an absolute covenant, in which case it extends also to interruption by persons claiming by title paramount to that of the landlord2. The qualified form is usually adopted, and under it the landlord is not liable for acts of persons claiming by title paramount to his title3, even though those acts are the consequences