This is a meta-template that can be used for user warnings.

{{uw3|reason=reason|page=Page}} yields:

Warning icon Please stop your disruptive changing. If you continue to reason, as you did at Page, you may be blocked from editing.

This template should be safesubst'd when using it inside of other templates, like this:

{{<includeonly>safesubst:</includeonly>uw3|reason=reason|page=Page}}