The artist:* tag should be the artist who created the image - that carries the 'copyright' and is what we use to keep track of who participated in the collab as an artist when badge time comes. But as the creator of the designs you absolutely should mention that they are your's in the description, and if you would like [we can add a description to the OC Tags so people know who owns them.](https://derpibooru.org/forums/tagging/topics/oc-tag-description-requests-read-post-1-before-requesting-18)