> There was a proposed standard for this but its name escapes me for the moment. XLink? It supports a feature known as extended links, which seems similar to w

> There was a proposed standard for this but its name escapes me for the moment. XLink? It supports a feature known as extended links, which seems similar to what you're describing. https://en.wikipedia.org/wiki/XLink https://en.wikipedia.org/wiki/XLink