even though the treaty that resulted with the blessing of corredan flame stopped the hunt of dragons for the purposes of harvesting their scales tellas and dragontears, there are those that are foolish enough to consider themselves slayers for hire.
nowadays tellas is harvested from naturally shed scales and it comes in different qualities depending on the number of times dragon had forged.
red tellas for instance signifies a seven times forged dragon. tricky part is that tellas' natural color doesn't always show, so it is often hard to distinguish a dragon's power.
some species use this as an intimidation element. rank two dragons with red scales usually live to see their future forgings.
so one might say there are no true rules for recognizing a dragon's rank...well...except for one.
one rule that stands above all.... if the scales are black, stay back.
see, younger dragons can emulate any scale color but black. that one is exclusive ownership of elder dragons- so in general, if the dragon is covered with black scales, you might want to consider whether you are exceedingly brave or merely suicidal