Sentence:  States were free to enact , within broad though ( perhaps ) determinate limits , their own rules as to the application of foreign law by their courts , to vary the <WSD>law</WSD> merchant , and to enact legislation with regard to many claims arising on the high seas . 
Meaning of the word marked with <WSD> tags:  the body of rules applied to commercial transactions; derived from the practices of traders rather than from jurisprudence