…paste formatting would be removed. That trick where you can select some text, click the ‘Paste Formatting’ paintbrush button, then paint that formatting on some other text is the cause of many problems I’ve seen in documents. Applying some random formatting to a chunk of text, instead of using the proper Style for that text, means that you end up with text with formatting that is in conflict with the Style it is in.
For example, you might have a bunch of text that is currently Body Text, but you want it to look like a Heading 1. What you should do is click in it and select the Heading 1 style. But because people see the convenient ‘Paste Formatting’ button, they paint the text to look like a Heading, instead of actually changing it to be a Heading. The next time they update the Table Of Contents, that text doesn’t show up because it’s not a real Heading, they get confused, say, “Word is stupid, I’m doing this stuff manually”, and then they’re lost forever.
Don’t use Paste Formatting.