The Quartus® Prime Standard Edition Default Settings File (.qdf) lists all of the default assignment settings. The default setting for an assignment is used until you change the assignment setting from the default setting. Once you change the assignment setting from the default setting, the assignment is shown in the Quartus® Prime Standard Edition Settings File (.qsf) with the assignment setting you specified. The default assignment setting remains in the Quartus® Prime Standard Edition Default Settings File, but the setting in the Quartus® Prime Standard Edition Default Settings File is the only setting processed.
The Quartus® Prime Standard Edition Default Settings File is located in the <drive>:/quartus/bin directory, but can also exist in the project directory. If the Quartus® Prime Standard Edition Default Settings File exists in the project directory the values of the Quartus® Prime Standard Edition Default Settings File in the project directory are used rather than the values of the Quartus® Prime Standard Edition Default Settings File in the <drive>:/quartus/bin directory.