It IS an invitation. Why are you broadcasting it other than to invite connections? You already know it and any computer you want to connect to it already knows it. It's only purpose is to solicit new connections. That's why you are supposed to turn off broadcasting it if you don't want anyone else to use it. Duh.
Incorrect. The SSID, or Service Set Identifier, identifies a particular wireless network in range. It does not, however, constitute or imply an "invitation" or authorization to connect to the network.