It depends on who you ask, truthfully.

The definitely BO markings are tier 2, certain tier 3s (NCL exclusives excluding ones that can be applied with piety, august maneater marks, july celestial raffle marks... i'm probably forgetting some), and the hybrid markings mottled stripes and mottled rosette. Rosettes, tier 4, count too, but they're usually counted on their own.

Piety markings and tier 6 markings are debated. Piety markings are breed-only for 11 months of the year but can be applied in November. Tier 6 markings solely come from an applicator. The argument for it being breed-only is that it's so expensive and risky to try to get a specific tier 6 from RMAs (someone got to a 7x rosette before getting the tier 6 they wanted). So if you had a certain tier 6 in mind, you'd be better to breed it on if possible.

People will tell you that you're wrong whatever you decide. It's up to your judgment.

You have liked this post!

Since BO is short for "breed only" a large amount of the community do not regard anything applicable as BO. I would not advertise them as "breed only" personally.

You have liked this post!

I personally consider them bo!

All markings in game excluding Mottled stripes and Mottled Rosette can TECHNICALLY be applied via an applicator. Tier 6 markings only come from RMA/RMR and at a low chance. Not as low as a "real" bo but still rather rare. I just consider them slightly more common bo!

You have liked this post!

My point here exactly lol. People cannot agree and both sides have strong opinions. I know a ton of people who have differing thoughts and there are a lot of both. If you're not rude about it, it doesn't really matter in the end. Like Espen said, everything except the hybrid markings can technically come from an app, so it's just down to what you think of these. It's a game. Do what makes you happy ^^

(Not trying to throw shade at anyone, I'm just amused.)

You have liked this post!

Tier 2 markings are all BO, and several tier 3 markings are BO! (Event BOs are categorized as tier 3, such as the bandit and dawn marking colors)
Event NCL markings and tier 6 both fall into the catagory of not being BO, but some people still consider them rare enough to work. Both are not BO, they're prestigious applicator markings. You can advertise them as BO but you really shouldn't.

You have liked this post!