2.1.1287 Part 1 Section 20.1.8.6, alphaModFix (Alpha Modulate Fixed Effect)

a.   The standard specifies that the alphaModFix value is clamped, so any value greater than 100 percent is interpreted as 100 percent, and any value less than 0 percent is interpreted as 0 percent.

Office modulates the alphaModFix value, so the value is interpreted as value modulo 100.