There are several flavors of fares applicable to different city pairs so review Expert Flyer carefully.
The 10 day minimum fares I was referring to are available without any date restriction and only a 7 day advanced purchase requirement. These are coded INN7M3T3.
There are also some slightly higher fares, coded INN3V3T3 that are only 3 day advanced purchase but are scoped in allowable dates of travel (not available for travel until Jun 26 but only to Sept 6 and then again Dec 16 to Jan 08). These have a 3 day or sunday stay minimum. Markets like YVR-PRG only have this fare, so I couldnt use it for dates in May, which would have worked well for me. So I have to OJ to one of the more limited number of cities with the 10 day minimum fare.