Usage
{{Ticket|ticket number|label}}
generates a link of the form:
[https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom&TicketNumber=number ticket number or label (if defined)]
This link is external to en.wikipedia.org, but in this case the template does not cause it to be followed by an external link icon. The template suppresses the arrow icon by placing the external link syntax between <span class="plainlinks">...</span>
tags.