If a specific column has been defined as a preferred row column, clicking on Preferred rows on/off
only those rows are displayed that have an entry in the column in question. This is usually the column for the article number (ERP number).[50]
[50] With ERP integration, the preferred rows are usually defined via the role rights setting (see Section 4.7.3.1, “ Roles: General " tab page ” in PARTsolutions Administration - Manual ).
If no setting has been set administratively, you have under Extras -> Settings [Preferences...]... -> Table -> Variable for preferred series [Variable for preferred rows], you have the option of defining the variable for the preferred series at user level (see ???).