A lot of gliders have two hooks. They are all made these days (and for many years) with a CoG hook for winching, some have an extra hook added further forwards for aerotow as a/t on a CoG hook can be 'interesting'. (in some cases the a/t hook is right in the nose)
Some older gliders have a compromise hook which does neither that well.
The a/t hooks usually don't have a back release, though the one in my glider does.