2.1.1351 Part 1 Section 188.8.131.52, style (Shape Style)
a. The standard allows a sp, pic or cxnSp to have similar formatting options defined in both the style and spPr elements.
In Office, shape properties defined on the parent element will override similar style components (lnRef, effectRef, fillRef, fontRef) defined in this element.
b. The standard allows similar text formatting properties to be defined for parent element sp by style or txBody.
In Office, child elements in txBody will override similar style properties defined by attribute fontRef.
c. The standard states that child element fontRef applies to parent elements pic, cxnSp and sp.
In Office, child element fontRef is not used for parent elements pic and cxnSp.