What is necessary in complex tables to accurately represent the structure of the table?

To accurately represent the structure of complex tables, using headers and ID attributes is essential. Headers help in defining the relationships between data cells, allowing screen readers to convey the correct context of the information to users. When proper header elements are applied, such as <th> tags, they can identify rows and columns, making it easier for assistive technologies to interpret the table's organization.

ID attributes serve to connect complex structures, often enabling users to understand which cell is linked to a header by referencing unique identifiers. This linkage is particularly important when tables are intricate or when certain cells span multiple rows or columns, as it clarifies how information is related within the table.

While accessibility features are important, they do not specifically denote how to represent the structure of tables. A table of contents and footnotes, while useful in other contexts, do not directly impact the representation and navigation of complex tables in a manner that aids in understanding their structure. Proper use of headers and ID attributes remains crucial in creating accessible and user-friendly complex tables.