There's a great list of Confluence Objects Accessible From Velocity on the Atlassian Developers site. I often refer to that page. However, the list is not exactly complete.

Scott Dudley wrote a handy user macro that displays all the available objects. I've improved a little on Scott's user macro by linking to the latest Confluence JavaDocs for each class.

Here's the user macro:


## Based on Scott Dudley's answer here:
## http://stackoverflow.com/a/23819584/1958200
##
## @noparams

#set($cashMoney = "$") ## just for display

#set($macroUtilClass=$action.class.forName('com.atlassian.confluence.renderer.radeox.macros.MacroUtils'))
#set($getContextMethod=$macroUtilClass.getDeclaredMethod('defaultVelocityContext',null))
#set($ctx=$getContextMethod.invoke(null))
#set($objects = $ctx.keySet().toArray())</pre>
<ul>
<ul>#foreach($p in $objects)</ul>
</ul>
&nbsp;
<ul>
<ul>#set($className = $ctx.get($p).getClass().getName().toString())</ul>
</ul>
&nbsp;
<ul>
<ul>
<li><code>$cashMoney$p.toString()</code> –
#if ($className.contains("$") == true || $className.startsWith("com.atlassian") == false)
$className
#else
#set($classUrl = "https://docs.atlassian.com/com/atlassian/confluence/atlassian-confluence/latest/" + $className.replace(".", "/") + ".html")
<a href="$classUrl">$className</a>
#end</li>
</ul>
</ul>
&nbsp;
<ul id="velocityObjects">#end</ul>
<pre>
<script type="text/javascript">// <![CDATA[
// Sort them - Confluence doesn't have velocity SortTool, so doing this client side.
AJS.toInit(function ($) {
var sort_by_name = function(a, b) {
return a.innerHTML.toLowerCase().localeCompare(b.innerHTML.toLowerCase());
}

var velocityObjects = $("#velocityObjects > li").get();
velocityObjects.sort(sort_by_name);
for (var i = 0; i < velocityObjects.length; i++) {
velocityObjects[i].parentNode.appendChild(velocityObjects[i]);
}
});
// ]]></script></pre>
<style><!--
/* add some style */
#com-atlassian-confluence #velocityObjects code {
margin: 0 2px;
padding: 0px 5px;
border: 1px solid #ddd;
background-color: #f5f5f5;
-webkit-border-radius: 3px;
-moz-border-radius: 3px;
border-radius: 3px;
}
--></style>
<pre>

And the resulting HTML displayed:

velocity-objects-in-confluence

Complete list of Confluence object available to Velocity

For completeness, I've copied over from a Confluence 5.5.x instance with links to the latest JavaDocs below. I won't be updating the list as you can use the user macro instead.