Specific effect is not given, but the Latin derivation seems to suggest that this affects and possibly augments the other spells being cast.
References from the canon
- Hermione cast this along with several other protective enchantments on the campsite in the woods next to the old Quidditch World Cup campgrounds (DH14).
- Casting this spell evidently became part of the routine protective enchantments used on their campsites during the hunt for the Horcruxes, because escaping from the Lovegoods' house, Hermione immediately began running in a circle around her companions, casting this along with other protective enchantments before they set up their tent (DH22).
Magic Type Concealment
Incantation Salvio hexia
Pronunciation SAL-vee-oh HEX-ee-ah
"salvia" L. without breaking + "hexia" hexes