Why is United States of American a defendant in sheriff sale?
I am learning about sheriff sale in Pittsburgh PA. In the sheriff sale list, there are a number of properties that are tax sales (Sci Fa sur Tax Lien, is the Sale Type) and United States of America is the defendant and city or school district is the plaintiff, what is going on? Can someone please explain?
Also, what is Sci Fa sur Tax Lien? thank you.