The header section of the weblet is rendered inside an HTML header tag. This property specifies the level of that header (h1, h2, h3, h4, h5, h6, h7 or h8). The header level has no effect of the visual appearance of the weblet but may be important for the semantic structure of your document. This may be important to how other systems such as search engines or assistive technologies process your page.
1, 2, 3, 4, 5, 6, 7 or 8.