Here place for default templates for alerts, groups and notifications. DO NOT TOUCH files here! Use user template overrides in main observium dir templates/ For example: # change current dirrectory to your observium dir cd /opt/observium # copy (or create) new template from defaults, for example HTML email notifications: cp includes/templates/notification/email_html.tpl templates/notification/ # edit copied file: nano templates/notification/email_html.tpl