That is an error in the programmers'/developers' code. If you compare these two URLS:
http://www.example.com/A/B/C/
http://www.example.com/A/B//C/
For instanceThey look different but if you navigatewere to: http://www.imywebsite.gov/sectionA/sectionB/section/page/ And then add a slash: http://www.imywebsite.gov/sectionA/sectionB//section/page/
The exact same page will load visit either, both of them would work in most modern browsers. This
This is something you want to fix. If you have the double slash it could confuse Google's web crawlers and make them think there is 2 versions of the page.