Help ends with Heading "Enabled for complex text layout (CTL)". Help missing for selections a) Show UI elements for East Asian writings b) Show UI elements for Bi-Directional writing c) Ignore system input language c seems new in 4.0, missing Help for a, b already in 3.6.6.2 and probably more early.
These sections are present in master help, they were added after the 4.0 string freeze, therefore cannot be backported.