If I make master slides in Impress, sometimes I see (wrong) or (good) after the name. Deleting that kind of slides is not possible. How can I do that?

How can I delete a wrong masterslide?

Hi- You can delete a custom master page only if it is not used in the presentation. A quick way to remove: display Master Pages in the SideBar, right click on the page to delete and “Delete Master”.