http://www.oneis3.com/posts/confluence-numbered-heading-bookmarklet.html

Confluence_numbered_section_headers.bookmarklet.js

(function() {
    function addSectionNumber (elem, sectionNumber, parentSection, level) {
        var sectionNumberStr = '';
        var sectionSpan;

        if (level > 1) {
            sectionNumberStr = parentSection + '.' + sectionNumber;
        } else if (level > 0) {
            sectionNumberStr = sectionNumber.toString();
        }

        if (level > 0 && jQuery(elem).find('.section-number').length === 0 ) {
            sectionSpan = jQuery('<span class="section-number">').text(sectionNumberStr + ' ');
            jQuery(elem).prepend(sectionSpan);
        }

        if ( level === 0 ) {
            jQuery(elem).find('h1').each( function(index, element) {
                addSectionNumber(element, (index + 1), sectionNumberStr, (level + 1));
            });
        } else if ( level < 6 ) {
            jQuery(elem).nextUntil('h' + level, 'h' + level + ',h' + (level + 1)).each( function(index, element) {
                addSectionNumber(element, (index + 1), sectionNumberStr, (level + 1));
            });
        }

        return;
    }

    addSectionNumber(jQuery('#main-content').first(), 0, '', 0);
})();