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This message is sent to one of the SMS gateways supported by the project (see https://dimagi.atlassian.net/wiki/x/fCnKfw). Also, when registering cases, it's highly recommended that a follow-up survey is sent to capture additional information to identify the case (name, etc.). This is described in Send a Welcome Message or Survey. When registering users, if the optional <username> is omitted, the name of the mobile worker will be the same as its phone number.
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