Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Reading the markerlight rules, I can't see it even being intended any other way. This was done on purpose, no doubt about it.

"All models firing at the target as part of this shooting attack" or "All weapons fired at the target as part of this shooting attack"

They make it clear that only a Tau Codex unit can activate the markerlights, it would have been all too easy to mention this under each individual rule or stipulate only Tau models get the benefit.