Description (converting data from one type to another) should include actual queries showing the conversion of

Conversions that will not result in a loss of data or precision may be completed implicitly, or without specific code performing the conversion. Explicit conversions must be hard-coded to be executable by the processor if the loss of data or precision is possible. Specific functions include

Conversion functions of dates also include format models that lay out a template for date and number conversions.

Conversions functions also include the NVL function that converts nulls to actual values, which can then be manipulated with numeric functions. 

Description should also illustrate complex transformation of data by including queries where functions are nested within each other.