The Language of Moths

Secrets are best kept when only those with secrets of their own can understand them.

— Unknown

They say the moths speak their own language. If you are clever enough, talented enough, or blessed enough, you may be able to learn it for yourself. It is the language of secrets, magic, and mysteries. And those who know it are privy to the greatest secrets and deepest knowledge of the world.

Shadow Signs

A language of secrets is, of course, itself, a secret. The source and process of learning the language of Moths is closely guarded by a mysterious organization. It is assumed, though not known for certain, that this organization is run by priestesses of Gwyfyn.
There are those who claim to know this ancient language, though any expert should be met with healthy skepticism. Nonetheless, many of these "experts" tend to agree on a few key pieces of information. The language of Moths is known to have both written and spoken forms but in addition to those, it is believed to make use of light and shadow. The words can be carved into stone and the meaning gleaned by some who know the language, but for the true masters, shining a light on the carvings can reveal a new meaning based on the shadows the characters cast. One message can have numerous words and phrases hidden within that change depending on the direction of the light and the angle of viewing.
Another material often used is cloth. Secret messages are stitched into fabric or hidden in lace designs which only an acolyte of the moth can decipher.
Even the spoken word of the language of moths can include this use of light and shadow, as the person speaking may add forms with their hands to cast secret messages on the ground. Across large distances, light can be used to convey messages between acolytes.