Here is where I will continue the detailed discussion of runes classification and the reasons for such class types.
Higher Class: 27 True Runes, which I would divide into three subdivisions
Unique/Special: Dawn, Twilight, Bright Shield and Black Sword
Middle Class: Cyclone, Mother Earth, Star, Rage, Thunder, Flowing, Condemnation, etc.
Lesser Class: Fire, Wind, water, Lightning, Earth, Ressurection, Blinking, Shield, Beast, Eight Devil
Attack Type: Elemental Sword Runes
Non-Rune related skills or adaptions of magic
Status Types: Turtle, Sunbeam, Phero, Charm, Prosperity, Skunk, etc.
Skill Runes (pertaining to talent, mutations, etc.): Rabid Fang, Spider Slay, Falcon, Boar, White Saint, Jongleur, Trickster, Killer, Shrike, Kite, Godspeed/Holy, etc.
These runes not related to the True Runes such as Elemental Swords are adaptations of magic used for practical purposes. The rune bearer manipulates the element of water to give the weapon that property. It is just an innovation on the usage of magic.
Skill Runes are basically individual skills and techniques, but also refer to innate abilities related to the very nature of the bearer. Note, that Bob has a Rabid Fang Rune which has the ability to maintain his human state. This is an adaptation of runic magic. Boar Runes cannot be used by anyone other than brawlers and Kite Runes can only be used by talented projectile users. They are typically not related to True Runes.
Whereas, the status type runes much like the Elemental Sword runes relate to runes through adaptations, but some also are based on the individuals latent talents. Let's use the Charm Rune as an example. Jeane bears striking beauty, the Charm Rune represents her latent ability to attract the male species. Now, let's look at the Turtle Rune. I believe that this particular rune is an adaptation of the properties of earth and allows protection from abnormal statuses inherent to the earth.