Rugby World Cup 7s
It was the main stand alone competition for rugby sevens until it was included into the Olympic Games since the 2016 edition.
After the inclusion in the Olympic Games World Rugby decided to end the World Cup.
In 2013, however, World Rugby decided to continue the World Cup, sliding it in 2018, to have a main tournament every 2 years.
The first official edition was held in 1993. However in 1973, as part of SRU's centennary celebrations, an International 7s Tournament was played and it was considered an unofficial World championship.
http://www.worldrugby.org/ - World Rugby official site
www.rugbyafrique.com - Rugby Afrique official site
asiarugby.com - Asia Rugby official site
www.rugbyeurope.eu - Rugby Europe official site
www.nacrugby.com - NACRA official site
www.oceaniarugby.com - Oceania Rugby official site
www.sudamericarugby.org - SudAmerica Rugby official site (former www.consur.org).
pl.wikipedia.org/wiki/Puchar_swiata_w_rugby_7 - Wikipedia pages about Rugby World Cup Sevens
en.wikipedia.org/wiki/1973_International_Seven-A-Side_Tournament - Wikipedia page about 1973 International Tournament
http://www.rwcsevens.com/ - Former Rugby World Cup Sevens official site. It was scanned with web.archive.org