The RIPE NCC is running their Resource Certification system for a couple of months now, and we've got quite a number of prefixes covered by ROAs in the repository by now. So I decided to have a look at how people are creating their ROAs and in particular how the 'Maximum Length' feature is used, which authorises the AS to deaggregate the prefix to the specified point. We compared the repository to the prefixes seen by our RIS route collectors. It gives a good indication how people are using this option, and what the effects are when people base routing decisions on validation results. You can read the article here: https://labs.ripe.net/Members/AlexBand/using-the-maximum-length-option-in-ro... I'm interested to hear if you think we should change our implementation, and what choice you think is the best. -Alex