What's the point of having a tail hole painted in the armor?

[Aegis]

Remember when the darklight and heavy darksteel armour came with armour plating for miqo tails on it?

Good times, good times.

[Felis]

Remember when the darklight and heavy darksteel armour came with armour plating for miqo tails on it?

Good times, good times.

There were also only 2 types of tails with fixed lengths. Short sun seeker tail and long moon keeper tail.