What information must retail clients be notified of when an exception to execution rules occurs?

When an exception to execution rules occurs, it is crucial for retail clients to be notified of the details of better overall results for clients. This requirement is grounded in transparency and client protection. Providing clients with information about better results ensures they are aware of how their order might have been handled in a way that could have led to more favorable outcomes compared to standard execution procedures.

Informing clients about the better results helps them assess the performance of their trades and understand the implications of deviations from expected execution practices. This disclosure also reinforces trust, as retail clients are made aware of the firm's efforts to optimize their trading experience, even when exceptions are necessary.

The other options, while potentially relevant in different contexts within trading operations, do not directly align with the specific requirement to inform clients about better overall results in situations where execution rules have been deviated from. Current market statistics, documentation of prior consent, and potential risks of execution delays all serve different purposes that may not directly address the need for transparency in the context of an exception to execution rules.