The namespace name http://www.idpf.org/2007/ops is used in the following EPUB specifications:
http://www.idpf.org/2007/ops
Open Publication Structure 2.0.1
EPUB Content Documents 3
EPUB Media Overlays 3
For more information about the development of EPUB, refer to Publishing@W3C.
For more information about XML namespaces, refer to Namespaces in XML.