Context : HH 223 is a knotty , wiggling nebular emission of \sim 30 \arcsec length found in the L723 star-forming region .
It lies projected onto the largest blueshifted lobe of the cuadrupolar CO outflow powered by a low-mass YSO system embedded in the core of L723 .

Aims : We analysed the physical conditions and kinematics along HH 223 with the aim of disentangling whether the emission arises from shock-excited , supersonic gas characteristic of a stellar jet , or is only tracing the wall cavity excavated by the CO outflow .

Methods : We performed long-slit optical spectroscopy along HH 223 , crossing all the bright knots ( A to E ) and part of the low-brightness emission nebula ( F filament ) .
One spectrum of each knot , suitable to characterize the nature of its emission , was obtained .
The physical conditions and the radial velocity of the HH 223 emission along the slits were also sampled at smaller scale ( 0 \aas@@fstack { \prime \prime } 6 ) than the knot sizes .

Results : The spectra of all the HH 223 knots appear as those of the intermediate/high excitation Herbig-Haro objects .
The emission is supersonic , with blueshifted peak velocities ranging from -60 to -130 km s ^ { -1 } .
Reliable variations in the kinematics and physical conditions at smaller scale that the knot sizes are also found .

Conclusions : The properties of the HH 223 emission derived from the spectroscopy confirm the HH nature of the object , the supersonic optical outflow most probably also being powered by the YSOs embedded in the L723 core .