PROVISO. The name of a clause inserted in an act of the legislature, a deed, a written agreement, or other instrument, which generally contains a condition that a certain thing shall or shall not be done, in order that an agreement contained in another clause shall take effect.

2. It always implies a condition, unless subsequent words change it to a covenant; but when a proviso contains the mutual words of the parties to a deed, it amounts to a covenant. 2 Co. 72; Cro. Eliz. 242; Moore, 707 Com. on Cov. 105; Lilly's Reg. h. t.; 1 Lev. 155.

3. A proviso differs from an exception. 1 Barn. k Ald. 99. An exception exempts, absolutely, from the operation of an engagement or an enactment; a proviso defeats their operation, conditionally. An exception takes out of an engagement or enactment, something which would otherwise be part of the subject-matter of it; a proviso avoids them by way of defeasance or excuse. 8 Amer. Jurist, 242; Plowd. 361; Carter 99; 1 Saund. 234 a, note; Lilly's Reg. h. t.; and the cases there cited. Vide, generally Amer. Jurist, No. 16, art. 1; Bac. Ab. Conditions, A; Com. Dig. Condition, A 1, A 2; Dwar. on Stat. 660.