Blue-pencil and Iron curtain

Blue-pencil verb - To show (something written) to be no longer valid by drawing a cross over or a line through it.

Iron curtain and blue-pencil are semantically related. In some cases you can use "Iron curtain" instead a noun phrase "Blue-pencil".

Iron curtain noun - An impenetrable barrier to communication or information especially as imposed by rigid censorship and secrecy; used by Winston Churchill in 1946 to describe the demarcation between democratic and communist countries.

Blue-pencil and iron curtain are semantically related. Sometimes you can replace phrase "Blue-pencil" with "Iron curtain", this phrases are similar.