The correct HTML for a textarea would be something like this:

<textarea name='content' rows='5' cols='50' id='requestedContent' class='form-control'><?php echo @$_REQUEST['content'] ?></textarea>

Let me know if that clears up your issue, or if you have any further questions.

Thanks!

Another help would be to push the autofill text onto a WYSIWYG editor textarea...

Code as follows:

<div>
    <br>
    Choose Content:
    <br>
    <select id="content" onChange="return setMail()">
    <option value="">Choose A Communication</option>
    <?php foreach ($communicationsRecords as $record): ?>
    <option value = "<?php echo $record['num'];?>"><?php echo $record['title'];?></option>
    </select>
    <?php endforeach ?>
</div>
<br>
<div>       
    Content:
    <br>
    <input type='textarea' name='content' rows='5' cols='50' id='requestedContent' class='form-control'><?php echo @$_REQUEST['content'] ?>
</div>

<script>
function setMail(){
    // find the dropdown
    var ddl = document.getElementById("content");
    // find the selected option
    var selectedOption = ddl.options[ddl.selectedIndex];
    // find the attribute value
    var mailValue = selectedOption.getAttribute("value");
    // find the textbox
    var textBox = document.getElementById("requestedContent");

    // set the textbox value
    if(mailValue=="1"){
        textBox.value = "<?php echo $record['content'];?>";
    }
}
</script>