It's easy to get frightened by the notion of "violating a ring" - even the term is pretty scary. Keep everything simple and you'll enjoy this far more!
One of the issues with being a beginner (at least this is what I'm finding) is that unless you've handled, shot and inspected lots of good (and bad) quality bows, it's really hard to visualise what the books (and forum members!) are telling you. When I made my first bow, I'd never even shot one before, let alone handled a well-made self bow. I was completely in the dark, so everything seemed far more dramatic than it needed to be.
What looks like a "ring violation" to you is probably absolutely nothing, while something you might miss would be a major red flag to an experienced bowyer. If you remove the bark and cambium with a scraper or edge of a knife carefully, I can't imagine you'd ever cause enough of a problem to break a bow. If you go at it with a hatchet, and dig all the way into a growth ring right in a very stressed area of the bow, you MAY encounter problems.
Have you seen any of the bows on here with gigantic holes going all the way through a limb? Handled with care, a bow can take a lot. If you DO "violate" a growth ring completely, either go down to the next ring and start again, or leave that particular area of the bow slightly wider to accommodate for the issue. Same with knots.
At this stage, you need to get some bows under your belt so that you can understand first hand what certain issues result in. Crack on with what you're making, and if there are some funky bits, or you dig a bit too deep somewhere, either it will explode there and you'll know "that was too deep - more care next time" or you'll know "well it didn't break. Obviously I didn't go far enough to cause a problem." Either way, you've learned something new about bow building that you can use next time.
But I realise none of that is what you asked haha
Ring "violation" is going THROUGH a ring into the next one. Most of the time the single back ring will be all sorts of thicknesses due to the bowyer not knowing how deep he's going the whole time. Remember also that when your bow is finished, and tillered, you'll need to sand it all over both before and during applying a finish. That will change the thickness of the growth ring as well. Plus different woods can take different amounts of violation. Yew for instance is essentially bullet proof when it comes to ring violations. There's no need to keep a single one all the way along, unless you're talking about something with a draw weight of 100# or so. I've found that ash can take a surprising amount of violation to it's back rings before it gives up. And even then, a bit of superglue and some binding can save you on a good day!
