On Tuesday, June 14, 2016 9:05 AM, from Patrick Boyle pboyle01@gmail.com:

USA Rugby is participating in the World Rugby 7s Trial laws. This may be temporary as it is a trial. It reads:

3.4 Players nominated as substitutes

A team may nominate up to five replacements/substitutes.

A team may substitute or replace up to five players.

A team may substitute the same player more than once as long as no more than 5 substitutions are made in total.

A good example is a recent USA 7s World Rugby Circuit game where Perry Baker started, Carlin Isles subbed on, then Perry Baker subbed back on. That is 2 substitutions. So there were 5 guys on the bench, and one player who started is subbed back on as in this example, only 4 guys on the bench in total could be used as Perry ‘took’ one of the subs.