An XHTML file that is well-formed but not valid: although the markup is structurally correct, the ID values for the header cells in thead (table header) are illegal because they start with a number instead of a letter or underscore. It is not clear how assistive technology responds to this. However, since the header cells define their scope by means of the scope attribute, assistive technologies should not have problems to find the associations between data cells and their headers. Validity error: ID attributes start with number Christophe.Strobbe@esat.kuleuven.be en Copyright BenToWeb 2004-2007 2005-10-05 accepted for end user evaluation Strictly Conforming Documents

This is a test case is intended to fail because the file is well-formed but invalid. However, it is not clear if this causes problems for assistive tecnologies.

 enduser

When navigating the table cells, can you find out the row and column headers for each cell?

If you can't find out the row and column headers, does this make the table unreadable? Please comment.

If not, what happened?

I don't know

 10 30 blindness

Depending on the browser or assistive technology, the user may not be able to find the row and column headers when navigating through the cells of the table.