Why are flags so similar?

There are no international flag design rules, so why are national flags so similar?### Notes ###There are a few more specific reasons for similar flags, but I do hope this video serves as a decent answer to the question in my own words.### Sources ###"Look Busy" Kevin MacLeod (incompetech.com)Licensed under Creative Commons: By Attribution 3.0 Licensehttp://creativecommons.org/licenses/by/3.0/"Long Road Ahead"Kevin MacLeod (incompetech.com)Licensed under Creative Commons: By Attribution 3.0http://creativecommons.org/licenses/b... Learn more about your ad choices. Visit megaphone.fm/adchoices