To send a public channel to archive, go to Administration – Basic Applications – Public Channels, open the channel page, click Edit, select Yes in the Archive field and click Save (fig. 1).
Fig. 1. Send public channel to archive
After you have saved these settings, the channel will be moved to the Archive folder and will become inactive. Users with permissions to view the channel will be able to open it and view the messages, but will not be able to add new messages.