In biology, cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
The doctype declaration should be the very first thing in an HTML document, before the <html> tag. The doctype declaration is not an HTML tag; it is an instruction to the web browser about what version of the markup language the page is written in. The doctype declaration refers to a Document Type Definition (DTD).
Tooltipster allows you to use any HTML markup inside your tooltips. It means that you can insert things like images and text formatting tags. Instead of a title attribute, use a data-tooltip-content attribute to provide a selector that corresponds to the HTML element of your page that should be used as content. This is your HTML: In your CSS file, add .tooltip_templates { display: none; } so that the content does not get displayed outside of the tooltip.