“ Thus a tradesman calls those who deal with him his “customers,” and the trade resulting as their “custom.” The word is also used for a toll or tax levied upon goods; there was at one time a distinction between the tax on goods exported or imported, termed magna custuma (the great custom) , and that on goods taken to market within the realm, termed parva custuma (the little custom) , but the word is now used in this sense only in the plural, to signify the duties levied upon imported goods. ”