Examples of invalid markup that could cause accessibility issues

example 1 - not well-formed

example from Tag Soup: How UAs handle <x> <y> </x> </y>. HPR reads this as a, b, d, c, e and seems to get very confused. I had to reload the page several times.

This is a sample test document (written a, b, c, d, e but sometimes read a, b, c, e othertimes a, b, d, c, e).

a b

c d
e

This is a sample test document. (written a, b, c, d, e but read as a, b, d, c, e). a b

c d
e

Example 2 - two headings with same id

I am having trouble with HPR reading the headings other than by using the keys to read the first cell in column. Isn't there a way to ask it to read the header associated with the cell each time a select a cell?

Table 7. Standard Heats and Free Energies of Formation, and Absolute
Entropies of Inorganic and Organic Substances
B. Organic Compounds
Compound State DHf o (kJ/mol) DGf o(kJ/mol) So (J/mol K) Class
Methane g -74.9 50.6 186 alkane [@@error]
Ethane g -84.5 -33.0 230 alkane
Propane g -104.0 -23.0 270 alkane
Butane g -127.2 -17.0 310 alkane
Pentane g -146.4 -8.4 349 alkane
Pentane l -173.2 -9.5 263 alkane
Hexane g -167.2 -0.3 388 alkane
Hexane l -198.8 -4.4 296 alkane
2-Methylpropane g -135.6 -21.0 295 alkane
2-Methylbutane g -154.4 -14.8 344 alkane
2-Methylbutane l -179.9 -15.2 260 alkane
2,2-Dimethylpropane g -166.0 -15.2 306 alkane
Cyclopropane g 53.1 104.4 237 alkane
Cyclobutane g 27.0 110.0 265 alkane
Cyclopentane g -77.4 38.6 293 alkane
Cyclopentane l -105.9 36.4 49 alkane
Cyclohexane g -123.0 31.8 298 alkane
Cyclohexane l -156.2 26.7 204 alkane
cis-1,2-Dimethylcyclohexane l -211.9 31.5 274 alkane
trans-1,2-Dimethylcyclohexane l -218.4 25.2 273 alkane

From Table 7, Part B

example 3 - two labels referencing the same input element

This passes the validator. It reads "first name: text" then "first name last name: text" because even though two labels exist, they both have the same "for" attribute value of "lname."

example 4 - missing end tag

Are there better examples that would cause issues for an assistive technology but not a stand-alone browser?

a paragraph with an unclosed code element will cause the same issues for everyone.

what about emphasis followed by code where emphasis isn't closed?

paragraph with an unclosed anchor element will cause issues for everyone.

closing the a and em and the code (creating overlap...)

example 5 - end tag for not opened element

following this paragraph is an end h3 but no open.

following this paragraph is an end p but no open

example 6 - literal is missing closing delimiter

Example deleted because it messes up the rest of the tests. When <a href="test>test</a> is the last test on the page, in HPR the code is displayed and no link is created. Firefox creates the link. When quotes are used later in the page, it acts as if <a> has not been provided, except for when I included example 9: all of example 7 and 8 disappeared and "image with 2 alt attributes - alt1 and alt2" became the text of the anchor. Bottom line - forgetting the end quote in an href can cause some seriously funky results.

example 7 - character data is not allowed here

some text in a paragraph

some text not in a paragraph

more text in a paragraph

example 8 - document type does not allow element X here; missing one of Y start-tag

table cell without table table row without table
  • list element without list type
    • emphasis without block

    example 9 - duplicate specification of attribute X

    alt1 image with 2 alt attributes - alt1 and alt2. HPR reads only the first.