You can also extract different parts of an existing svg and use (clone) them elsewhere on the page.
https://developer.mozilla.org/en-US/docs/Web/SVG/Reference/E...
I've used this to succinctly define a Sierpinski carpet on Wikimedia Commons a while ago: https://commons.wikimedia.org/wiki/File:Sierpinski_carpet_6....
That file was able to lock up or crash most SVG renderers back then.