award criteria - clarification of weight and other codelist values?

Many of our buyers struggle with understanding the way award criteria can be defined in eForms.

Is there a guide available somewhere that explains (how to use) the different criteria parameters (weight value, fixed value, threshold value), as well as their codelists?. E.g. when using "weight value" as criterion, the weight type must be specified with a value selected from the number weight codelist, but the different possibilities are a bit obscure.