Attributes definition for non-numerical attributes

[jmhorcas]

Currently, the definition of attributes requires to specify a Domain, a Range, a default value, and a null_value?

This should be ok for numerical attributes (price, performance) but not for other types of attributes such as for example a simple "note" (a string). For example the Glencoe tool supports a "note" attribute in the features for documentation.

How can this be modeled within the current Attributes definition?