2009 Manual 3-114
Some years back (see “C ¼ and Curves” 1/3/2006) I started a thread that talked about the “straight lines” run between opposing ¼ Corners to set the Center ¼ corner. I believed then (and still do) that the east-west line SHOULD be curved (on the latitudinal arc). Most folks disagreed, and many pointed out that we are generally only talking about 1.5-2 TENTHS of a foot at the C¼ anyway (and I agree with that obsevation in general).
Here's what the NEW Manual says:
3-114. To subdivide a regular section into quarter-sections, run straight lines from the fixed quarter-sections corners to the opposite corresponding quarter-section corners. The point of intersection of the lines thus run and fixed will be the corner common to the several quarter-sections, or in other words, the legal center of the section. This method of subdivision is outlined in 43 U.S.C 752(2)(cl.2) and 753(cls. 1 and 3). In this application, “straight lines” implied “lines of constant bearing” (43 U.S.C. 752(2)). (Emphasis added)