group sms-service : keyword
keyword = <word>
Services are identified by the first word in the SMS Each '%s' in the
URL corresponds to one word in the SMS message.
Words are separated with spaces. A keyword is matched only if
the number of words in the SMS message is the same as the number of
'%s' fields in the URL. This allows you to configure the gateway
to use different URLs for the same keyword depending on the number of words
the SMS message contains.