Yes, capitals are legal.
On Aug 15, 2013 1:23 PM, "Matt T. Proud" <notifications@github.com> wrote:

> In exporter/gmond_collector.go:
>
> > @@ -84,7 +86,7 @@ func (c *gmondCollector) Update() (updates int, err error) {
> >  		for _, host := range cluster.Hosts {
> >
> >  			for _, metric := range host.Metrics {
> > -				name := strings.Replace(strings.ToLower(metric.Name), ".", "_", -1)
> > +				name := illegalCharsRE.ReplaceAllString(metric.Name, "_")
>
> You are omitting the lowercasing. Is that intended?
>
> —
> Reply to this email directly or view it on GitHub<https://github.com/prometheus/node_exporter/pull/3/files#r5787896>
> .
>