Fixes by subject · 13 techniques
How to Fix Tables and Data
A data cell that does not know its header is a number with no meaning attached.
Sighted readers resolve a table by eye, tracking up a column and across a row without thinking about it. A screen reader can do the same thing on request, but only when the relationship between each cell and its headers is in the markup rather than in the layout. That is why the subject earns a page of its own even though W3C publishes very few table techniques, which is why the list below is short. It covers marking header cells as headers, setting scope, captioning tables, and associating a complex cell with more than one header. It also covers the documented failures that come from laying data out with white space instead of a table. Two of those are advice rather than obligation, because a caption is not required in every case, and a small table with one clear header row does not need scope on every cell.
All 13 techniques
They run in technique order, and each one carries a tag. Sufficient techniques satisfy a rule. Advisory ones help without being required. Failures document a specific way of getting it wrong. None of them is mandatory, because W3C publishes techniques as documented ways of meeting a criterion rather than the only ways, so your own approach conforms as long as it meets the criterion.
- H39Sufficient1.3.1Caption data tables so their purpose is clear
- H43Sufficient1.3.1Connect complex table cells to headers with ids
- H51Sufficient1.3.1Use real table markup for tabular data
- H63Sufficient1.3.1Add scope to table header cells
- T3Sufficient1.3.1Format plain-text headings with standard conventions
- F33Failure1.3.1, 1.3.2Do not fake columns with white space characters
- F34Failure1.3.1, 1.3.2Do not format tables with white space characters
- F46Failure1.3.1Never put th or caption in a layout table
- F49Failure1.3.2Do not use layout tables that read as nonsense
- F90Failure1.3.1Do not mis-wire headers and id attributes in tables
- F91Failure1.3.1Do not style table headers instead of marking them up
- PDF6Sufficient1.3.1Tag PDF tables as real tables
- PDF20Sufficient1.3.1Repair mistagged tables with Acrobat's Table Editor
More on Tables and data
The other 13 subjects
Knowing the technique is not the same as knowing you need it.
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