Dh_modaliases is useful for packages that ship third-party kernel modules, either in binary form, or as sources (with e. g. DKMS). It extracts the modules' modaliases from either the compile .ko files themselves (for packages which ship them in compiled form, using modinfo), or from a package file debian/packagename.modaliases.

This enables software which is looking for missing driver packages (such as Jockey or the operating system installer) to identify which package(s) will provide a driver for a piece of hardware, identified by its modalias.