Just for the record... I Do Not necessarily recommend having guests wear an identifying tag

How does your church or group interact or not interact with first time visitors? It can be quite intimidating on both sides (for the visitor and the community member). Hopefully it’s not all left up to the leader or pastor. Here are some practical ideas for connecting with visitors to your church.

https://www.evangelismcoach.org/6-ways-to-follow-up-on-first-time-church-visitors/