Any deviation from net neutrality must be transparent and clearly intelligible, and have effects that are verifiable.
If an ISP deviates from net neutrality, it must inform its end users in a transparent and clearly intelligible fashion. This applies equally to cases where end users and CAPs are differently treated. The practical effects of different treatment of Internet traffic on end users must be communicated clearly to them. (Can their service be compromised? If so, when, how often and how badly? Will their usage of specific services be blocked or degraded? And so on.) End users must have some way of verifying the information provided as, otherwise, they would be unable to compare offerings or make rational decisions between tariff options.
It must also be possible for CAPs to verify the actual effects of deviations from net neutrality on their offering, particularly when preparing business cases. Transparency for CAPs reduces the barriers to market entry, encourages innovation and competition, and is inherent in best-effort Internet services.
 This implies that the information on deviations is publicly available and accessible to third parties.