pro·vi·so / prəˈvīzō/ • n. (pl. -sos) a condition attached to an agreement: he left his unborn grandchild a trust fund with the proviso that he be named after the old man.

PROVISO

A condition, stipulation, or limitation inserted in a document.

A condition or a provision in a deed, lease, mortgage, or contract, the performance or non-performance of which affects the validity of the instrument. It generally begins with the word provided.

A proviso clause in a statute excepts something from statutory requirements, qualifies the statute, or excludes some potential area of misinterpretation.