EPUB CFIs can point to non-existing virtual elements at the very beginning of an element container and at the very end of an element container. See http://www.idpf.org/epub/linking/cfi/epub-cfi.html#sec-path-child-ref for a more in-depth explanation.
EPUB CFIs can point to non-existing virtual elements at the very beginning of an element container and at the very end of an element container. See http://www.idpf.org/epub/linking/cfi/epub-cfi.html#sec-path-child-ref for a more in-depth explanation.