Final answer:
To ensure space for binding in a manual's layout, the designer must modify the margin space to include a binding or gutter margin, allowing the text to remain visible when the pages are bound.
Step-by-step explanation:
To ensure that there will be a designated space for the binding in the layout of an instructional manual, the designer needs to modify the manual's margin space. When creating the layout for a manual or any bound document, it is crucial to account for the binding margin or gutter margin. This additional space on the inner edges of the pages accommodates where the pages are bound together, allowing the text and important content to remain visible and not be cut off or hidden in the spine of the finished product. As outlined in the detailing of text features like margin space for various teaching aids and customizations, the proper layout and accommodation of binding needs are essential for a professional and functional document.