They Take the Vex out of Vexillology

The Internet’s largest site devoted to the study of flags.
It may sound like trainspotting, but I’ve been sucked in a bit by the precision of the facts.
For example, the US flag isn’t just Red, White, and Blue. It’s:
Cable No. 70180 Old Glory Red
Cable No. 70001 White
Cable No. 70075 Old Glory Blue
For the Aussie flag (shown above):
“The outer radius of the 7-pointed stars in the Southern Cross should be 1/14 the width of the fly (the “height” of the flag). For the 5-pointed star it should be 1/24. The Commonwealth star should be 3/20. In each case, the inner radius should be 4/9 of the outer radius.”