Frank Law and Legal Definition
Frank is a signature, stamp, or mark affixed to mail as a substitute for postage. It also denotes the privilege of sending certain mail free of charge, accorded to certain government officials, such as members of Congress and federal courts. In this sense, it is also referred as franking privilege. The 'franking privilege' is the right to send mail postage-free. This privilege is granted to various officers, not for their own special benefit, but with a view to promote the public good.
