It's both a namespace problem and the question of whether it isn't better to use different tags to describe different things, outright, instead of nesting the different tags in a d-tag, just so that you can pretend that they're all using the same identifier.
Discussion
also, if you have your own event kind that doesn't clash with existing kinds, I think it's fine to define the semantics for let's say the o-tag to be whatever you want it to be