code/Debug/Helper/Data.php
public function getBlockName(Mage_Core_Block_Abstract $block)
    {
        $blockName = $block->getParentBlock() ?
            "{$block->getParentBlock()->getNameInLayout()}_{$block->getNameInLayout()}" :
            "{$block->getNameInLayout()}";

        if ($block->getBlockAlias()) {
            $blockName .= "_{$block->getBlockAlias()}";
        }

        return $blockName;
    }
public function getBlockName(Mage_Core_Block_Abstract $block)
    {
        $blockName = $block->getParentBlock() ?
            "{$block->getParentBlock()->getNameInLayout()}_{$block->getNameInLayout()}" :
            "{$block->getNameInLayout()}";

        if ($block->getBlockAlias()) {
            $blockName .= "_{$block->getBlockAlias()}";
        }

        return $blockName;
    }
Formats the blockname used in the observer::onBlockToHtml method

@param Mage_Core_Block_Abstract $block
@return string