Do SVG docs support custom data- attributes?

Question

In HTML5, elements can have arbitrary metadata stored in XML attributes whose names start with data- such as

. Is th

Answer 1

there is a more general mechanism.

svg supports desc elements which may contain arbitrary xml from other namespaces. link instances of this elements or child nodes from you own namespace by dependent ids or refid attributes.

this is the relevant part of the spec (5.4).