app/code/community/Aoe/TemplateHints/Model/Renderer/Comment.php
public function render(Mage_Core_Block_Abstract $block, $blockContent, $id) {

        $helper = Mage::helper('aoe_templatehints/blockInfo'); /* @var $helper Aoe_TemplateHints_Helper_BlockInfo */

        $path = $helper->getBlockPath($block);
        $blockInfo = $helper->getBlockInfo($block);

        $wrappedHtml = sprintf(
            "\n".
            '<!-- [START: %1$s] %4$s'."\n".'%5$s -->'.
            "\n".
            '%3$s'.
            "\n".
            '<!-- [END: %1$s] %4$s -->'.
            "\n",
            $id,
            $blockInfo['cache-status'],
            $blockContent,
            $helper->renderTitle($blockInfo),
            $this->renderBox($blockInfo, $path)
        );

        return $wrappedHtml;
    }
public function render(Mage_Core_Block_Abstract $block, $blockContent, $id) {

        $helper = Mage::helper('aoe_templatehints/blockInfo'); /* @var $helper Aoe_TemplateHints_Helper_BlockInfo */

        $path = $helper->getBlockPath($block);
        $blockInfo = $helper->getBlockInfo($block);

        $wrappedHtml = sprintf(
            "\n".
            '<!-- [START: %1$s] %4$s'."\n".'%5$s -->'.
            "\n".
            '%3$s'.
            "\n".
            '<!-- [END: %1$s] %4$s -->'.
            "\n",
            $id,
            $blockInfo['cache-status'],
            $blockContent,
            $helper->renderTitle($blockInfo),
            $this->renderBox($blockInfo, $path)
        );

        return $wrappedHtml;
    }
Render template hint

@param Mage_Core_Block_Abstract $block
@param $blockContent
@param $id
@return string|void