Is It Proper to Nest a Inside a Element? In Bootstrap, it's common to use horizontal forms. However, one might encounter the need to avoid creating IDs for each element. As a workaround, some consider nesting a inside a with a custom CSS class to force it to behave as a block element. Specifically, the following code demonstrates this approach: Email Copy after login And the custom CSS: .block { display: block; }Copy after login The Correct Approach According to the HTML specification, a element is not allowed to contain a element. From the specification: "Content model:Phrasing content, but with no descendant labelable elements unless it is the element's labeled control, and no descendant label elements." Phrasing content refers to text and elements that mark up text at the intra-paragraph level, including , , , and , among others. is not included in this list. Therefore, nesting a inside a is considered incorrect HTML. It may result in unexpected behavior or validation errors.
