a short code is a way to send a sms message without typing a whole phone number.
no error message, but messages to 2653 (coke for a code under a cap) just don't seem to make it. google updated their shortcode, so that could be why they weren't working.
http://www.google.com/intl/en_us/mobile/sms/
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then again, it looks like it still isn't working with the new google shortcode
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