DMN12 — Need attribute for human and external decisions

Normally, a valid executable model requires a value expression for every decision. However, human decisions and external decisions, by definition, exclude a value expression. To allow validation to skip such decisions, an attribute identifying a decision as human or external would be useful.

unnecessary - value expression can be in natural language

According to the spec, one can use the expressionLanguage attribute set to the value http://www.omg.org/spec/DMN/uninterpreted/20140801 to indicate that the value expression of a decision is not to be interpreted.