The first step is to create the document. To do this, open a text editor and enter the following text (or download the source file referenced above):

<?xml version="1.0" encoding="UTF-8"?>
<cmrl xmlns:dotgo="http://dotgo.com/cmrl/1.0">
  <match pattern="*">
    <message>
      <content>Hello world!</content>
    </message>
  </match>
</cmrl>

Save the document as “index.cmrl.”

So what does it all mean? Let's have a look at the document, line by line.

Line 1:  <?xml version="1.0" encoding="UTF-8"?>

This line indicates that the document is an XML document, which is necessary because CMRL is a variety of XML. An opening line like this is required of any XML document and hence of any CMRL document.

Line 2:  <cmrl xmlns:dotgo="http://dotgo.com/cmrl/1.0">

This line indicates that the document is a CMRL document. A line like this is required of any CMRL document.

Line 3:    <match pattern="*">

This line introduces the match tag, which is a fundamental aspect of CMRL. A match specifies a pattern against which the query is compared to determine how the query is to be routed or resolved. In this case, the match pattern is the “default” match pattern (represented by the wild-card character “*”) and there are no other match patterns specified in the document, so any query that is presented to the document will satisfy this match.

Line 4:      <message>

This line introduces the message tag, which is another fundamental aspect of CMRL. Every terminating match must contain one (and only one) terminating node, of which a message is the simplest example. A message must contain content (i.e. the body of the message) and may in addition contain other constructs (which are beyond the scope of this document).

Line 5:        <content>Hello world!</content>

This line contains the content of the message. In this case, the content is the simple text string “Hello world!” enclosed by the opening <content> and closing </content> tags.

Line 6:      </message>

This line closes the <message> tag opened in line 4.

Line 7:    </match>

This line closes the <match> tag opened in line 3.

Line 8:  </cmrl>

This line closes the <cmrl> tag opened in line 2.

The next step is to install the document. To do this, transfer the document to the root directory of your web server, i.e. to the same directory that contains the root “index.html” of your web site. Make sure that the document is named “index.cmrl” and that permissions are set to allow appropriate access to the document, and test that the document is accessible by opening it in a web browser (e.g. at http://example.com/index.cmrl).

NOTE: Some web servers (such as Microsoft IIS) will not allow access to .cmrl files until a proper MIME type is added to their configuration. For Microsoft IIS, you can add a MIME type for .cmrl files by following instructions at

http://support.microsoft.com/kb/326965

Use “.cmrl” (without the quotes) for the extension and “text/xml” (without the quotes) for the MIME type. Similar steps can be taken when using web configuration control panels such as Plesk. If you do not have access to your web server configuration, then contact your web hosting service to request this change.

The next step is to validate the document. To do this, first direct your web browser to http://dotgo.com/Publishers/Resources/CMRLValidator and then type your domain name into the input box under “Validate by URI” and click the button “Validate.” You should receive a response indicating that your index.cmrl file is valid. If not, then verify that the document exactly matches the listing of section 3.1, that the document is named “index.cmrl,” and that permissions are set to allow appropriate access to the document.

The final step is to test the document. To do this, text your internet domain name to the phone number DOTCOM (368266)—or to one of the the phone numbers DOTEDU (368338), DOTGOV (368468), DOTNET (368638), or DOTORG (368674) as appropriate. For example, to access the internet domain “example.com,” text “example” to the phone number DOTCOM (3682266). (Of course, you should substitute your actual internet domain name in place of “example,” and you should text to the phone number corresponding to your actual top-level domain.) You should receive the response “Hello world!” Congratulations—you have implemented your own mobile service.

So how did it work? First, the system used the first word of the query “example” and the phone number DOTCOM (368266) through which the query was received to determine that the query should be routed to example.com. Next, the system retrieved the file index.cmrl from example.com. Finally, the system compared the remainder of the query (i.e. everything after “example,” which in this case was an empty string) against the match patterns specified in the file index.cmrl in order to resolve the query. In this case, there was only one match pattern specified in the file index.cmrl—the default match pattern—which resolved to the message “Hello world!” returned by the system.

Open a text editor and enter the following text (or download the source file referenced above):

<?xml version="1.0" encoding="UTF-8"?>
<cmrl xmlns:dotgo="http://dotgo.com/cmrl/1.0">

  <match pattern="">
    <message>
      <content>Welcome to the DOTGO example.</content>
    </message>
  </match>

  <match pattern="red">

    <match pattern="circle">
      <message>
        <content>You have selected a red circle.</content>
      </message>
    </match>

    <match pattern="square">
      <message>
        <content>You have selected a red square.</content>
      </message>
    </match>

  </match>

  <match pattern="green">

    <match pattern="circle">
      <message>
        <content>You have selected a green circle.</content>
      </message>
    </match>

  </match>

  <match pattern="engine">
    <engine href="http://dotgo.com/cgi-bin/examples/current_time.cgi"/>
  </match>

  <match pattern="rss">
    <rss href="http://dotgo.com/support/documentation/example2/example.rss"/>
  </match>

  <match pattern="*">
    <message>
      <content>Nothing relevant here.</content>
    </message>
  </match>

</cmrl>

Again save the document as “index.cmrl,” and again install and validate the document as in the previous example.

Now let's see what this document does. We will again take as an example the internet domain “example.com,” although of course you should substitute your actual internet domain name in place of “example,” and you should text to the phone number corresponding to your actual top-level domain.

The query “example” produces the response “Welcome to the DOTGO example.” The system again used the first word of the query “example” and the phone number DOTCOM (368266) through which the query was received to determine that the query should be routed to example.com, and the system again retrieved the file index.cmrl from example.com, and the system again compared the remainder of the query (which was again an empty string) against the match patterns specified in the file index.cmrl to resolve the query. But in this case, the empty string was matched to the “null” match pattern (i.e. the empty string), which resolved to the message “Welcome to the DOTGO example.”

The query “example red circle” produces the response “You have selected a red circle.” In this case, the second token of the query is matched to the match pattern “red,” and the third token of the query is matched to the match pattern “circle,” so the match is unambiguous.

The query “example circle” produces the response “Did you mean 'red circle'(1) or 'green circle'(2)?” In this case, the second token of the query is matched to the lower-level match pattern “circle” but is ambiguous between the higher-level match patterns “red” and “green,” so the match is ambiguous, and the system seeks to resolve the ambiguity.

This query also illustrates the “hyperlink” feature of DOTGO. In reply to the above response, the query “1” is equivalent to the query “example red circle.” Similarly, the query “2” is equivalent to the query “example green circle.” In this case, the hyperlinks were generated automatically by the system, although CMRL allows arbitrary hyperlinks to be specified.

The query “example square” produces the response “You have selected a red square.” In this case, the second token of the query is matched to the match pattern “square,” skipping the higher-level match pattern “red” since the match to “square” is unambiguous.

Both the queries “example grean cirkel” and “example g c” produce the response “You have selected a green circle.” In these cases, the queries are matched to the match patterns “green” and “circle.” In general, the system seeks to obtain matches using phonetics and abbreviations as well as by direct comparison (although it is possible to turn this feature off, requiring exact matches, which is beyond the scope of this document).

The query “example engine” produces a response similar to “It is 9:18 UTC on April 12, 2008.” (but with the current time and date). In this case, the query is matched to the match pattern “engine,” which terminates in an “engine” tag that references a cgi program running on the DOTGO servers. An engine is any web-based application program and can return arbitrary output in response to arbitrary input. Here the engine simply returns the current time and date.

The query “example rss” produces the response “DOTGO News and Blog. Reply (1) for latest news entry and (2) for latest blog entry.” In this case, the query is matched to the match pattern “rss,” which terminates in an “rss” tag that references RSS feeds hosted on the DOTGO servers.

The query “example encyclopedia” produces the response “Nothing relevant here.” In this case, the query does not match any of the specified match patterns so is matched to the default match pattern. A document does not have to have a default match, but in general it is a good idea to include one, to handle queries that cannot otherwise be resolved.