If you put the same information in multiple pages it can lead to problems later on. For example: imagine you share an email address in multiple pages where you want people to contact you. If later you need to change that email address, it will take you more time because you'll have to find and edit each of the pages where it's shared. And if you forget to update one of the pages then people will use the outdated email address.
To solve this problem, make a separate page and link to that page from any page that needs to. For example: you could make a 'Contact' page with the email address and other contact details of your group, and in any other page where you want people to contact you, you just link to that contact page. See how to make links on the wiki.