  The composition of giant planets is imprinted by their migration history and
the compositional structure of their hosting disks. Studies in recent
literature investigate how the abundances of C and O can constrain the
formation pathways of giant planets forming within few tens of au from the
star. New ALMA observations, however, suggest planet-forming regions possibly
extending to hundreds of au. We explore the implications of these wider
formation environments through n-body simulations of growing and migrating
giant planets embedded in planetesimal disks, coupled with a compositional
model of the protoplanetary disk where volatiles are inherited from the
molecular cloud and refractories are calibrated against extrasolar and Solar
System data. We find that the C/O ratio provides limited insight on the
formation pathways of giant planets that undergo large-scale migration. This
limitation can be overcome thanks to nitrogen and sulphur. Jointly using the
C/N, N/O and C/O ratios breaks any degeneracy in the formation and migration
tracks of giant planets. The use of elemental ratios normalized to the
respective stellar ratios supplies additional information on the nature of
giant planets, thanks to the relative volatility of O, C and N in disks. When
the planetary metallicity is dominated by the accretion of solids C/N* $>$ C/O*
$>$ N/O* (* denoting this normalized scale), otherwise N/O* $>$ C/O* $>$ C/N*.
The S/N ratio provides an additional independent probe into the metallicity of
giant planets and their accretion of solids.
