One place that I commonly find half dovetails (unwedged) is in common floor joist systems using +/- 2" wide rough sawn material. Typically there is at least one half dovetail close to the center of the floor joist pattern. I assume it's to keep the summer beams straight.

We just got done taking down a c1840 barn in West Virgnia near Cheat Lake. It has wedged half dovetail joints at the tie beam post connections. It also had a wall girt to the right and left of the threshing floor that had a half dovetail joint which apparently supported a tie beam which ran parrallel to a swing beam in each bent to the right and left of the threshing floor. The paired beams which no longer exist would have been 4' OC and the tie beam that sat in the dovetail appears to have been an 11x11" timber! I've never seen anything like it. Has anyone else?

Rudy R. Christian