  We critically look at Senthil Fisher constructions of quantum number
fractionization in cuprates. The first construction, while mathematically
correct is of limited relevance to cuprates. The second one has a missing local
U(1) symmetry. Once this aspect is repaired, it reveals itself as the U(1) RVB
gauge theory construction of quantum number fractionization. An approximate
local $Z_2$ symmetry arises in the spin sector for a reason very different from
Senthil and Fisher's. The charge sector continues to have the local U(1)
symmetry and the metallic spin gap phase of the 2d cuprates may, in principle,
carry (irrational) fractional charge $e^* \neq e$ obeying Haldane's fractional
exclusion statistics like the 1d models.
