Table structure (table)
Semantic tables must convey their structure programmatically—using native table elements (<table>, <thead>, <tbody>, <tfoot>, <th>, <td>) or equivalent ARIA roles (role="table", role="row", role="cell").
div instead of thead:
This table lacks a proper <thead> element (instead it uses a <div>):
| Person | Most interest in | Age |
|---|---|---|
| Chris | HTML tables | 22 |
| Dennis | Web accessibility | 45 |
| Sarah | JavaScript frameworks | 29 |
| Karen | Web performance | 36 |
| Average age | 33 | |