A school uniform is read as rules, belonging and the self you were in your school years. Wearing one as an adult is often taken as feeling judged or tested again.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.