  We analyze recently proposed formalisms which use nilpotent variables to
describe and/or generalize qubits and notion of entanglement. There are two
types of them distinguished by the commutativity and or anti-commutativity of
basics variables. While nilpotent commuting variables suit the new description
of the qubits and entanglement, the anticommuting do not, but they can be used
to describe generalized objects - superqubits. A squbit, in the present
context, is a version of superqubit introduced to cure some of problematic
properties of the superqubit.
