A birth certificate is read as proof of identity and of where you began. Dream books link it to questions of belonging, or to a new beginning being made official.
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.