2.1.1147 Part 1 Section 19.5.13, bldGraphic (Build Graphics)

a.   The standard places no restrictions on what the spid attribute refers to.

PowerPoint requires that the spid attribute reference a chart or diagram that is present on the slide.

b.   The standard places no restrictions on what the grpId attribute refers to.

PowerPoint requires that the grpID attribute reference a group that is present in the timing tree.

c.   The standard places no restrictions on the relationship between the spid attribute, the grpId attribute, and the parent bldLst element.

PowerPoint requires that the combination of the spid attribute and the grpId attribute on a given bldGraphic element form a unique pair within the parent bldLst element.