1.   Market data providers may only apply differentials in fees if those are determined on the basis of a categorisation of clients and provided that all of the following conditions are met:

(a)	the criteria used to set forth categories are based on elements that are factual, easily verifiable and sufficiently general to be applicable to a group of clients;

(b)	the margin for market data, established in accordance with Article 3, is the same for all clients within the same category;

(c)	differences among categories are clear and clients are able to understand the category to which they belong;

(d)	only one category is applicable per client.

2.   Where there are multiple and significant different extra costs for the provision of the market data to the same client, market data providers may add an increment to the applicable fee determined by the extra costs incurred.

3.   Market data providers may only grant discounts or other temporary reductions of fees provided that those discounts or reductions are based on elements which are factual, easily verifiable and sufficiently general to pertain to more than one client.