Systems and methods are disclosed herein for combining a first annotation and a second annotation in an electronic document. The first annotation is received and corresponds to a first portion of the electronic document. The second annotation is received and corresponds to a second portion of the electronic document. A first position of a layout rendering of the first annotation is determined, and a second position of a layout rendering of the second annotation is determined. The first position of the layout rendering of the first annotation is compared to the second position of the layout rendering of the second annotation. When the first position conflicts with the second position, the first annotation and the second annotation are combined to form a stacked annotation.