i have their guide, and it doesn't give actual language. Here's what they say:

<<The Kindle platform supports guide items for defining the cover, the table of contents (TOC), and the start reading location (”Go to Beginning”).
Amazon does not recommend adding additional guide items to the OPF file, because they will be grayed out in the menu options and may cause customer confusion.
IMPORTANT: Guide items, especially the TOC guide item, do not replace the table of contents.>>