The difference by which scientists classify Sneasel and Weavile is not the red crown and collar that most trainers use to distinguish the two, for it is in truth little more than an accessory, which can be lost and must be hand-crafted, typically from luminescent materials on the night of the pokemon's evolution. Instead, the evolution is distinguished from its predecessor by its razor-sharp claws, capable of not only carving up other pokemon, but leaving messages in tree bark, boulders, and other natural material, for it is their strange writing which makes a Weavile.
The messages which Weavile leave for one another are not written in emulation of the Unown, like the alphabets of humans, nor can they be understood as pictographs. It originated as a code and uses scratches wholly unlike those of men as a means of cryptography, for Weavile are thieves and pack hunters, and therefore benefit mightily from secrecy. Yet any secret spread too widely is bound to be discovered, and there have always been Weavile willing to leak their codes to weasel out of punishment.
In lands where Unown and literacy already existed, this led to little more than the rounding up of the local Weavile gang, at least until the pokemon got wise and changed the meaning of their scratches completely. But in many isolated lands around the world, humans have been fascinated by the very idea of leaving messages in a permanent form, and learned to write in scripts scratched out by Weavile claws. In these lands, Weavile left theft behind for the privileges of scribes, for their claws scratch out words in far more surfaces than any human tool, but used their writing for palace intrigue nearly as often as they did for public administration.