On another forum, there was some confusion about the various icons present in and around the Red Dragon 3D model...
The four-sided spike icons are bones which are placed at strategic locations, just like our own skeletal system, to aid in the support and locomotion of our own body. I use a bright red
color for the right side of the body and bright green
for the left side of the body. The colors are not really necessary, but it helps with handling and posing of the 3D character.
The control rig are the orange
colored rings and/or circle icons scattered around the outside of the body. Each control ring or circle is used to position/pose several bones at once. This helps to speed up the animation process-- so the animator doesn't have to position each and every single bone in the 3D character.
There's much, much more detail/information concerning rigging a 3D character. I'll stop here for now so I don't bore some of you to death.