Dendrimeric and related molecules that have the same atomic connectivity from exterior to core, P-C-1-J(1)-C-2-... Z (P peripheral group, J juncture, C connector, Z core) can be described completely by a highly compact fractal notation, which is of the general form Pf(J1,J2...) (C-1.C-2...)Z. In this paper, we show how to describe molecules that deviate slightly from the symmetry of a related parent molecule, by use of parenthetic expressions (iX), (dX), and (YrX) which designate atoms or molecular groups that are inserted, deleted, or replaced by other groups in the parent.