That all depends on if you're planning a celebration with family and friends after.  If your announcements include a post-elopement celebration invitation, including a link to your registry is acceptable. If you're only doing announcements and have no intention of celebrating with anyone, asking for gifts is kind of tacky, in our opinion. (But that's just us!)  That said, if there are a few practical things you need, it never hurts to create a registry in case you get personal requests from close friends and family for a gift list.