metadata
"In today's digital world, metadata is like the blank back of a printed photo. This digital file that accompanies an image is a "place" to "write" information about the image -- who made it, who owns the copyrights, what the image depicts, who is in the image, where it was made, when it was made and even camera settings used to create it. "
"Metadata is like the information about a new car that you find on the sticker in the window. It includes items that lets you know the model type, model year, mpg, included options, extras, price, and other basics about the vehicle. It helps you understand what you get in the package."
Who, what, why, where, how, how much....
The Library of Congress code is a categorization of this analogy that could be considered metadata, the date is metadata, the reference URL is metadata and the writer's name is metadata for this analogy. Get it? Metadata is data that describes and give context to other data. This is one example, there are many more possible.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.