I think to use the fetus the @ should represent a kernel, object, but in a generic form such / representing the top of the tree.
I can also see the term becoming controversial such male and female vs. plug and socket. Some see the former as blatantly sexual and the latter requiring dirty mind to be sexual.
Maybe it's best to hold off on that reference until we get more voices to chime in.
LOL I was mostly thinking of the swiss roll but I know it's only called rocambole in Brazil. It's got all sorts of names all over the world according to Wikipedia