There are two common misconceptions surrounding the Wiccan Rede that I'd like to address today.
The first misconception is that it's something all witches/pagans follow, or even that it's something that all witches/pagans must follow, and if they don't? Well, then they're not a real witch/pagan. Frankly, I don't understand how this makes sense to anyone - especially when it comes from 'elders,' or the more influential people in the community who really should know better.
Wiccans are pagan, that's true, but we know not all pagans are Wiccan. Likewise, not all witches are Wiccan. So why should all witches/pagans follow the Wiccan Rede, even if they're not Wiccan? (Heck, when you really get down to it, the Wiccan Rede is not even something truly emphasisied in all Wiccan traditions!) Yes, some non-Wiccans choose to follow the Wiccan Rede, and there's nothing wrong with that. However, there are a number of traditions and individual paths which have their own morals, ethics, and so on. The Wiccan Rede is not a part of every tradition, and it doesn't need to be. It really is that simple.
Beyond that, let's look at the meaning of the word rede. Rede doesn't mean law, and it doesn't mean commandment - instead it means something more along the lines of advice or counsel. A word of advice is a lot different than a set in stone law, so even if someone didn't follow the rede in every situation, would it really make them any less of a Wiccan/witch/pagan?
The second misunderstanding is from those who whittle the Rede down to two words, "harm none." It is impossible to never cause harm, but luckily the Rede does not say that. The Rede says "an it harm none, do what ye will" or, alternatively, "an ye harm none, do what ye will." An means if, and ye of course means you. If you harm none, do what you will. In other words? If whatever it is you're planning to do doesn't cause harm to anyone, go for it. The Rede is permissive, not restrictive.
If it does cause harm? The Rede doesn't actually say what to do in that situation, but we can assume that the advice is implying that one should carefully weigh their options in such a situation - perhaps that unnecessary harm should be avoided. However, no where does it say that causing any harm must always be avoided. An additional line to the Rede has been floating around for a while now "an it cause harm, do as ye must." Although it's not an 'official' part of the Rede, perhaps it does help clarify the spirit of the Rede more than just saying "harm none" does.
Now, to be fair, no, I am not a Wiccan, and no, I do not personally incorporate the Rede into my path. So perhaps it isn't my place to be commenting on what the Rede does or does not mean, since I don't even follow it... but, well, I figure since it's pushed on me so often I might as well toss my two cents in on the matter now and again. There are several different ways one could interpret the Rede, but I think taking the "harm none" approach just doesn't do it justice.