From https://lists.oasis-open.org/archives/office-comment/200903/msg00155.html :
Where the SVG specification may not meet the needs of ODF, there are
two options. First, ODF can simply extend SVG using its own
namespaced elements and attributes. Second, the SVG WG is interested
in working with the OpenDocument TC to add missing features to the SVG
specification. We are already planning on adding some common
features, like connector elements, which we see are supported in ODF,
and we are open to hearing more use cases and requirements.