They take a pen and if lines, groups of words, paragraphs, or one or more pages match the definition of a Cabinet confidence, then they cross out the text. In those instances, and in every situation, we need to ask ourselves whether the words or paragraphs can legitimately be read or not. That's the principle we apply.
Evidence of meeting #6 for Finance in the 43rd Parliament, 2nd session. (The original version is on Parliament’s site, as are the minutes.) The winning word was documents.
A video is available from Parliament.