Use function top_httphead to include headers in pages.

htdocs/admin/agenda_xcal.php

htdocs/cashdesk/affIndex.php

htdocs/cashdesk/facturation_dhtml.php

htdocs/cashdesk/tpl/ticket.tpl.php

htdocs/core/ajax/check_notifications.php

htdocs/core/antispamimage.php

htdocs/core/js/datepicker.js.php

htdocs/core/js/lib_head.js.php

htdocs/core/js/lib_notification.js.php

htdocs/core/js/select2_locale.js.php

htdocs/core/js/timepicker.js.php

htdocs/core/lib/functions.lib.php

htdocs/document.php

htdocs/install/inc.php

htdocs/main.inc.php

htdocs/paybox/lib/paybox.lib.php

htdocs/paypal/lib/paypal.lib.php

htdocs/projet/jsgantt_language.js.php

htdocs/support/inc.php

htdocs/theme/eldy/style.css.php