The fluid measurement % can only be used on non-textual elements.

Using a fluid measurement percentage is not restricted to non-textual elements; it can be applied to both textual and non-textual elements in CSS. The percentage value is highly useful in achieving responsive design, where elements can scale relative to their parent container or by the dimensions of the viewport.

For textual elements, setting properties like width, height, and even padding or margins in percentages allows for a more fluid layout, enabling the text content to adapt dynamically as the browser window resizes. This capability is essential for modern web design, where maintaining accessibility and usability across various devices is a priority.

Therefore, it's accurate to state that percentages can be applied to both types of elements, supporting a flexible and adaptable approach to layout design.