When you create your AlertFirst account, you will create a text keyword that your contacts can text to our short code in order to opt-in to messages that you want to send them. When your contact sends a text message to us with your opt-in keyword, it will be checked against the keywords in our database. If the keyword matches one in the database, your contact will be opted in to receive your messages. Your contact will then receive a text message back informing them that they have opted in to receive your messages. At this point, you can legally send your contact a text message anytime. To opt-out, your contacts can text back STOP, QUIT, CANCEL, or STOP ALL. You also have the option to manually remove them from your stored contact list. If a contact wants to receive messages from you again at some point in the future, they must opt-in again using the keyword you created. A list of all your keywords can be found under Manage Account, Text Auto-Reply Keywords.