A Wal-Mart employee-training videotape may prove a key piece of evidence for Visa and MasterCard in the upcoming trial over debit card rules, which had a dress rehearsal of sorts on Friday.

The tape shows the difference between Visa and MasterCard debit cards and other types — and instructs cashiers to encourage customers to use the other types.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.