Investigated the behavior of "Text snaps to characters grid".
* If the grid type is grid(line and characters) and the "snap-to-characters" attribute is ture, the Asian character is centered in the single cell, while the non Asian text is centered within as many cells as required.

* If the grid type is grid(line and characters) and the "snap-to-characters" attribute is false, the Asian character is not centered in the single cell, but what is the behavior for the non Asian text?

Below is the screenshot from MS Word


Figure 1,Text snaps to character grid

Figure 2, Specify line and character grid

It seems that there is a special behavior for non Asian text when the text doesn't snap to the character grid.
Where can I get some clues?