  Charge density wave (CDW) order has been shown to compete and coexist with
superconductivity in underdoped cuprates. Theoretical proposals for the CDW
order include an unconventional $d$-symmetry form factor CDW, evidence for
which has emerged from measurements, including resonant soft x-ray scattering
(RSXS) in YBa$_2$Cu$_3$O$_{6+x}$ (YBCO). Here, we revisit RSXS measurements of
the CDW symmetry in YBCO, using a variation in the measurement geometry to
provide enhanced sensitivity to orbital symmetry. We show that the $(0\ 0.31\
L)$ CDW peak measured at the Cu $L$ edge is dominated by an $s$ form factor
rather than a $d$ form factor as was reported previously. In addition, by
measuring both $(0.31\ 0\ L)$ and $(0\ 0.31\ L)$ peaks, we identify a
pronounced difference in the orbital symmetry of the CDW order along the $a$
and $b$ axes, with the CDW along the $a$ axis exhibiting orbital order in
addition to charge order.
