What does the invitation code of the gold-seeking app mean?

Looking for the gold app invitation code, you need a special pass when registering.

The invitation code is equivalent to entering the registration code when you use a software. It's the same as an invitation in real life. Only when you receive the invitation code can you register your account. After the forum is open to invite registration, the invitation code becomes a necessary condition for registering the forum. If you want to register an ID, you must get a valid invitation code.