1. Under no circumstances may you ever attack another vampire. Exceptions are clan projects for a takedown of one. But personal qualms are not and never allowed to leak into your actions.
2. Biting vampires is illegal. It is a waste of AP better used for robbing. (Okay, so you may bite vampires if you've just deposited money and still have some AP over. Or if you're on your way to get the 200 BP you need for Holy Water or the BP needed for Stamina. Basically the few logical, rational exceptions. But that's it, and don't push it.)
3. Siring vampires is illegal. No Splinter may lust for blood. The exception to this rule is simple: You may lure a victim to your biter link every once in a while, but only to easily introduce them to the game - not for your personal gain. You are then also obligated to aid this new vampire and obligated to, if they are trustworthy at all, introduce them to the ideals of the Splinters of Dusk - and possibly thence recruit.
4. Stealing from a Shard is a waste of AP. And wasted AP will lower your reputation - however, this is only a minor 'rule' that can, in theory be breached. Afterall, you are getting money that was intended for you anyway.
5. Telling other people about gekkonids is illegal. The only protection that the clan can offer lies in this rule. Break it, and lose your honour. You will never be given a chance to rest again if you break this rule. (You can of course tell people about anyone that explicitely and openly is a gekkonid.)