... however, and this agreement is made upon the express understanding and consideration, that said second party shall regard and treat this agreement as confidential, and will use all reasonable precaution ... their said mills at Niagara Falls, and as favorable facilities and accommodation in all respects as are afforded by the party of the first part to the millers of Buffalo and Black Rock. And also ... classifications are arranged on this principle, provided competition by water, rail or other land transportation does not demand a modification. It is, as a rule, not to the advantage of a railroad...