Elsewhere he writes why he uses the term kernel rather than memeplex:

Your kernel is the set of assertions you agree with. In theory, since no one can physically stop you from thinking for yourself, everyone could have a different kernel. But in practice, people are social animals, they get most of their assertions from others, and their kernels cluster.

Therefore, we can speak of "prototype" kernels, implying patterns of agreement across social groups. Methodism, for example, is a "prototype" under this definition. Not all Methodists agree on all assertions factual, ethical, or metaphysical, but there is clearly a general pattern of consensus.

These patterns correspond to the networks by which assertions are transmitted between individuals. Let's call a assertion in transmission a "packet." If you "accept" the packet, it means you agree with the assertion. If you "reject" it, you don't.

(There's another word that means "transmitted belief." I've made up my mind about this word: I don't like it. Mainly because it makes me sound like a dork. The mere auditory tone of the word, its mouth-feel, is awful, and its various declensions (such as "memeplex") are even worse. But "meme" also implies a sort of scientistic pretense that I find unwholesome, an attempt to intimidate the reader through the bogus authority of jargon. I prefer to borrow words from the computer business specifically because I think of programming as a trade, not a science. )