Notice how the last sentence in this paragraph is the only one that is general enough to cover the entire paragraph. Each sentence in the paragraph provides specific support for the final assertion: A dress code is a good idea.
Sometimes the topic sentence is not found at the beginning or end of a paragraph but rather somewhere in the middle. Other times there isn‘t a clear topic sentence at all. But that doesn’t mean there isn’t a main idea. It’s there, but the author has chosen not to express it in a clear topic sentence. In that case, you’ll have to look carefully at the paragraph for
clues about the main idea. You’ll learn more about this in Section 4.