Decoders
Source systems use cryptic codes to represent certain values. A Decoder table can be used as a lookup table to apply a more meaningful name to a code. It also allows for a single translation value when codes are represented differently in each source system.
When you create a Decoder to translate one coding system to another, create it in the same way you create a composer used in measurements to give a larger spectra to an item as you are able to drill up and drill down in a dimension.