Open the House 1.rvt file and the Params_to_keep.txt file from the downloads page.
In the Revit file, go to the toolbar and open the Project Parameters menu: Manage → Project Parameters.
Observe the parameters contained in the Revit file.
Note that there are two parameters with the same name: AF_FireRating, however, one is a Project Parameter and the other is a Shared Parameter.
Also note that there are two project parameters with very similar names:Wall Finish and Wall Finish 2

In this tutorial we want to delete the AF_FireRating Shared Parameter and also the Wall Finish 2 Project Parameter.
Close the Project Parameters menu.
In the Revit file, go to the toolbar and open Clear Parameters: Toolbox → Clear Parameters.

Move the following parameters into the Discard list:
AF_FireRating (Shared Parameter)Wall Finish 2 (Project Parameter)
Save the above settings into a txt file by clicking Browse and saving to a file namedParams_to_keep.txt.

Hit the button save to save the settings into the Params_to_keep.txt.

You’ll notice that the Save button becomes green to highlight the the current settings in the window match the settings in the Revit file and Parameters file.
You’ll notice that the AF_FireRating (Project Parameter) has been colored blue to call attention to the existance of two parameters with the same name.