15.11.4 Vertical Glyph Orientation of ODF 1.0

The paragraph is:

	The style:glyph-orientation-vertical property specifies the
	vertical glyph orientation. The property specifies an angle or
	automatic mode. The only possible angle is 0, which disables
	this feature.

First, I do not understand "vertical glyph orientation".   Is this 
the same as "7.27.3 glyph-orientation-vertical" of XSL?

Second, the schema fragment obviously allows "auto" as a permissible 
value.  

Third, what does 0 disable?  This property?

Cheers,
-- 
MURATA Makoto (FAMILY Given) <>