Here place for user templates for alerts, groups and notifications.

Default templates stored in includes/templates/ <- DO NOT TOUCH files here
Use this dir for overrides.

# 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

FORMATS

Notifications uses Mustache/CTemplate syntax.

Examples and demo see here: https://mustache.github.io/
But note, not all features of mustache supported.
Supported:
 * standart php comments
 * {{! %^ }} - intext comments
 *  {{var}}  - escaped var
 * {{{var}}} - unescaped var
 * {{var.subvar}} - dot notation vars
 * {{.}}     - implicit iterator
 * {{#var}} some text {{/var}} - if/list condition
 * {{^var}} some text {{/var}} - inverted (negative) if condition

Groups and alert templates uses xml syntax.

Examples see in includes/templates/ dir.