Font size variables: I have a question concerning the GuiXT font variables. In the SAP GUI options I use the "Arial monospaced for SAP, 10" (Enjoy Theme) font.
The GuiXT system variables show:

V[_fontsize_x]   8
V[_fontsize_y]   15

What is the meaning of these values?

These are the pixel values (width and height) of the characters that SAP GUI uses to calculate the field positions.