Field help (GENVACPIO) 

This flag is used to initialize the "Priority" flag of the wave resulting from a generic wave.
This parameter is used, when launching a wave, to create the associated missions with the priority defined for the wave instead of the priority defined on the mission types (see mission parameters).

 SEEINFO This setup only concerns missions with a picking type (PKOMVT, PKOPRC and PKOSHP) and missions with a merging of flows transfer type (TRFMERG). All the other mission types will apply the setup of the missions.