Slate (writing) expensive. Slate (writing) A slate is a thin piece of hard flat material, such as the rock also called slate, that is used as a medium for writing. The rock is “a metamorphic rock created by the recrystallization of the minerals in shale from clay to parallel-aligned, flat, flake-like minerals such as mica”. The writing slate consisted of a piece of slate, typically either 4x6 inches or 7x10 inches, encased in a wooden frame. A precise date range for writing slates of this type has not been established. Usually, a piece of cloth or slate sponge was used to clean
I-name I-name I-names are one form of an XRI — an OASIS open standard for digital identifiers designed for sharing resources and data across domains and applications. I-names are human readable XRIs intended to be as easy as possible for people to remember and use. For example, a personal i-name could be "=Mary" or "=Mary.Jones". An organizational i-name could be "@Acme" or "@Acme.Corporation". One problem XRIs are designed to solve is "persistent addressing" — how to maintain an address that does not need to change no matter how often the contact details of a person or organization change. XRIs accomplish this