Protocol of the URL. If empty and $1query set, the protocol is http. Leave both this and $1query empty to list all external links.
MediaWiki:Apihelp-query+exturlusage-param-protocol
Z WikiSkripta FJFI ČVUT v Praze
Protocol of the URL. If empty and $1query set, the protocol is http. Leave both this and $1query empty to list all external links.