A grid may also be a physical quantity. In this case, the magnitude is a numeric grid, and the units are either scalar, meaning the same unit applies to all numbers, or mixed, meaning that one set of units applies to each element.
ANTIK-USER> #_#m(1.0 2.0 3.0)_km
#_#m(1000.000000000000000d0 2000.000000000000000d0 3000.000000000000000d0)_m
ANTIK-USER> #m(#_1.0_km #_2.0_s #_3.0_kg)
#m(#_1000.000000000000000d0_m #dPT2.000s #_3.000000000000000d0_kg)
See Physical Quantities for more details on physical quantities, keeping in mind that whereever a scalar magnitude is shown there, a grid may be used instead.