The "Quality Check Codes" are used to store against a "Quality Test" to confirm exactly what checks need to be done. Within these, Values can be pre-defined and stored against the Check so that when the "Quality Test" is created, you can confirm the Target Result based on your set Values against the Check Code which can help where set results are expected per check and reduce the need for a user to manually type (which also reduces differing results every time if posted by different users).
From the "Role Center", in Setup, click into "Quality Check Codes" and create a new 20 character CODE and a Description for the check that is required. Per line, include the Unit of Measure if necessary. Finally, for Type, from the dropdown, select the option that you want to use for the result. The options are: 'Lookup', 'Decimal', 'Integer' and 'Text'. Where 'Lookup' is selected and all the line details are populated, in the ribbon, select Values. Here you can define the options you want to be able to select from when adding the Check against a "Quality Test".
When using Quality Check Code on "Quality Tests", dependant on which Result Type you choose depends on what results you can store. Check out the Quality Tests menu heading for more information.