Every SharePoint 2013 Web Application has a specific property we can use to specify how SharePoint should render the label on top-left of every page.
This property is not exposed by the UI but you can change it using PowerShell.
The name of this property is: SuiteBarBrandingElementHtml
This property is a string property that accept any Html Element. So you can customize it in many way.
My typical use is for differentiate Developement Environment by Production ones.
For example you can type a PowerShell script like that to adjust Suite Bar for a quality environment:
$wa = Get-SPWebApplication -Identity "https://myfqdn.web.app"
$wa.SuiteBarBrandingElementHtml = "<div class=""ms-core-brandingText"">myfqdn.web.app <b>(quality)</b></div>"
$wa.Update()
That's all.
