How do I get to this dialog box?
From X Manager or X Manager for Domains
Click Tools > Keyboard Maps.
In the Keyboard Maps dialog box, click Map Modifiers.
Administrators can also configure Keyboard Maps from the Domain Definitions tab.
An X server uses a modifier map to identify special keys known as modifiers. A modifier map contains a set of keycodes being used for each type of modifier. The X protocol defines 8 types of modifiers: Shift, Lock, Control, Mod1 (Alt), Mod2 (Mode Switch), Mod3 (Meta), Mod4 (Super), and Mod5 (Hyper). The map supports up to four keycodes for each modifier. In practice, two keycodes are sufficient, because most (if not all) keyboards only have two keys that perform Shift, Control, or Alt functions.
Some keyboards include Meta, Super and/or Hyper keys. Applications that use these keys (notably emacs) usually treat Mod3 as Meta, Mod4 as Super, and Mod5 as Hyper. In Reflection X, by default, Mod3 is defined (as Meta_L and Meta_R keys) but Mod4 and Mod5 are left undefined.
To map a modifier
Click a table cell to enable that cell's drop-down control.
Select a Keysym from the drop-down list. Reflection X looks up the keycode for each X Keysym in the keymap table.