What's a "guide icon"?
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A "guide icon" provides you with a link to consolidated reference material (a guide) regarding whatever you are currently viewing. Guides can be developed for all kinds of things, such as roles, departments, and processes. It's a rather unique looking icon combining a book and a light bulb. The book indicates reference material exists to help you. The light bulb is to remind you that it's a "good idea" to click it.