5   Page and Screen Design

Heading Attributes

When deciding on the attributes of each level of heading in the heading hierarchy, make sure that the reader will be able to easily distinguish one level from another. Make sure:

• the size runs from biggest to smallest as you descend in the hierarchy
• at least three points of type size separate each level of heading, for example, 18 point, 15 point, and 12 point (otherwise readers may be unsure of what level they’re looking at)
• the typeface runs from boldest to lightest as you descend in the hierarchy

Keyword headings – We’ve used another type of heading in this guidebook that we call keyword headings (like the one labeling this paragraph). They are not fifth-level headings because they can be used at any level in the hierarchy.

On the Web, the user’s browser determines the typeface and type size of each heading level found in a file. Each of the major browsers has a default, but these can be reset by the user.