Some anchors let plugins modify the value of a variable that is to be used later in the code. Let's take a look at a simple example, where we allow plugins to format a title that will be displayed on the page:

<code php>
<?php
	// First define the anchor
	define_anchor( "formatTitle" );

	// $title could be a value grabbed from the database, for example
	$title= "Line's Music Blog";
	$title= call_anchor( "formatTitle", $title );
?>
</code>

Now, if one were to create a plugin that modified this title in some way, it would look like this:

<code php>
<?php
	hook( "formatTitle", "myFormatting" );

	function myFormatting( $title )
	{
		return '<h1>' . $title . '</h1>';
	}
?>
</code>

Whatever value is returned by the plugin function will replace the original value of the variable.

<code php>
<?php
	echo $title;
	// prints <h1>Line's Music Blog</h1>
?>
</code>

Note too, that the value sent by ''call_anchor()'' can be of any type. If you need to send multiple values, supplying an array offers an easy workaround:

<code php>
<?php
	hook( "anchorName", "modifyAnchor" );
	
	// Call anchor with multiple values
	call_anchor( "anchorName", array( 'val1', 'val2', 'val3' ) );

	// Example plugin function
	function modifyAnchor( $vals )
	{
		$val1= $vals[0];
		$val2= $vals[1];
		$val3= $vals[2];
	}
?>
</code>