Awhile back a forum regular asked what I meant by "visual cues" when talking about using grids for placement of "eyebrows, decks, initial caps, and other visual cues." Basically, visual cues or readers' cues are simply all kinds of devices used to entice readers into a story or alert them to specific things in a publication. For example, an eyebrow or kicker above a column that says "Product News" alerts the reader immediately that what follows is news about a product (as opposed to a tutorial, editorial, or other type of story). A kicker might serve as a department or section head in a newsletter, for example, a regular column called "Nuts and Bolts" or "Q&A."
Initial caps and pull-quotes help to draw readers into a story. End signs cue the reader that the story is at an end. Jumplines and Continuation Heads let the reader know when a story continues on another page and where to pick up reading again.
Color can be a visual cue. For example, you might have a series of brochures that are color-coded based on the product line or service they address. Graphics can provide visual clues. You could use a stop sign or a bomb icon through a software manual to indicate "hey, this is an important note that you must read." Fonts can provide visual cues when used consistently, such as setting main headlines, subheads, opening paragraphs, captions, etc. in specific font styles and sizes throughout a document.
Visual signposts, another name for readers' cue, provide many ways to help a reader find their way around a document. Explore artwork, titles, paragraph organization, character emphasis, and explicit navigation as forms of visual cues.