How to set up the "generic" grading type?

The generic grading type is a type of grading, where every numeric entry is counted into average with its value.
E.g.1: If the school uses merely grades and a student gets grades: 1 and 5 his average will be 3.
E.g.2 If the school uses percent and a student gets 20% and 40% , his average will be 30%.
See: Assignment types: Grades, Points and Percent

First select "generic" in the grade book settings.

Next define how the final grade should be calculated. Example for the use of points and percent /average is calculated in percent/:

This is how we set the final grades calculations up in the grade book setting in "other". Final grades can be naturally represented in numbers or letters. Use dots to define decimal separator.

We see that the final grades are calculated according to the rules we had set above: