2.1.1659 Part 4 Section 220.127.116.11, style (Shape Style)
a. The standard states that child element fontRef applies to parent elements pic, cxnSp and sp.
In Office, the fontRef child element is not used for parent elements pic and cxnSp.
b. The standard allows a sp, pic or cxnSp element 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.
c. The standard allows similar text formatting properties to be defined for parent element sp by the style or txBody element.
In Office, child elements in the txBody element will override similar style properties defined by child element fontRef.