(5)Requirements should be laid down with respect to the systems of trading venues allowing or enabling algorithmic trading. However, their specific application should take place in conjunction with a self-assessment to be conducted by each trading venue since not all trading models present the same risks. Therefore, some organisational requirements may not be appropriate for certain trading models although their trading systems could be supported to a certain extent by electronic means. In particular, the specific requirements to be set in relation to request-for-quote systems or hybrid systems should be considered according to the nature, scale and complexity of the algorithmic trading activity undertaken. Equally, more stringent requirements should be established by the trading venues where appropriate.