An invitation is a written or verbal request asking someone to go somewhere or to do a specific task. It is formally calling an individual or group of individuals to be present at an event or activity. Thus, invitation cards or letters must be informative enough so readers could comprehend the best way possible. Yes, the potential attendees could inquire and call for clarifications, but there's a great difference when you present all the information correctly. When it comes to invitation details, include important information such as the time, location, and how to RSVP.