2.1.1687 Part 1 Section 126.96.36.199, rSp (Row Spacing (Array))
For additional notes that apply to this portion of the standard, please see the notes for ST_UnSignedInteger, §188.8.131.52(a).
a. The standard says rSp is used only to set row spacing in equation arrays even though it is also allowed as a child of the matrix element.
In Word, rSp is used to set row spacing in both equations arrays and matrices.
b. The standard states that rSp "specifies spacing between rows of an array eqArr; it is used only when rSpRule is set to 3 or 4. If this element is omitted, single line spacing is used in the array ..."
Word interprets the phrase "this element" in the statement to refer to "rSpRule", as in "if rSpRule is omitted, single line spacing is used in the array ..."