What does this statement //! [number] mean?
<p>I have seen In many project some programmers use <code>//! [1]</code>, <code>//! [2]</code>, ..., <code>//! [n]</code> in their code but I have no idea what this could mean.</p>

<p>I’ll be grateful if someone point out the use of those comments.
this is a snipe code:</p>

<pre><code>BlockingClient::BlockingClient(QWidget *parent)
    : QWidget(parent)
{
    hostLabel = new QLabel(tr("&amp;Server name:"));
    portLabel = new QLabel(tr("S&amp;erver port:"));


    QString ipAddress;
    QList&lt;QHostAddress&gt; ipAddressesList = QNetworkInterface::allAddresses();
    // use the first non-localhost IPv4 address
    for (int i = 0; i &lt; ipAddressesList.size(); ++i) {
    }
    // if we did not find one, use IPv4 localhost
    if (ipAddress.isEmpty())
        ipAddress = QHostAddress(QHostAddress::LocalHost).toString();

    //...
    connect(hostLineEdit, SIGNAL(textChanged(QString)),
            this, SLOT(enableGetFortuneButton()));
    connect(portLineEdit, SIGNAL(textChanged(QString)),
            this, SLOT(enableGetFortuneButton()));
//! [0]
    connect(&amp;thread, SIGNAL(newFortune(QString)),
            this, SLOT(showFortune(QString)));
//! [0] //! [1]
    connect(&amp;thread, SIGNAL(error(int,QString)),
            this, SLOT(displayError(int,QString)));
//! [1]

    QGridLayout *mainLayout = new QGridLayout;
    mainLayout-&gt;addWidget(hostLabel, 0, 0);
    setLayout(mainLayout);

    setWindowTitle(tr("Blocking Fortune Client"));
    portLineEdit-&gt;setFocus();
}

//! [2]
void BlockingClient::requestNewFortune()
{

    getFortuneButton-&gt;setEnabled(false);
    thread.requestNewFortune(hostLineEdit-&gt;text(),
                             portLineEdit-&gt;text().toInt());
}
//! [2]

//! [3]
void BlockingClient::showFortune(const QString &amp;nextFortune)
{
    if (nextFortune == currentFortune) {
        requestNewFortune();
        return;
    }
//! [3]

//! [4]
    currentFortune = nextFortune;
    statusLabel-&gt;setText(currentFortune);
    getFortuneButton-&gt;setEnabled(true);
}
//! [4]
</code></pre>
