taken from HTML5 A vocabulary and associated APIs for HTML and XHTML Editor's Draft 27 October 2009

4.9.1 The table element

Status: open issues around @summary, additions to cell. API, and @orientation

Categories

Flow content.

Contexts in which this element may be used:

Where flow content is expected.

Content model:

In this order: optionally a caption element, followed by either zero or more colgroup elements, followed optionally by a thead element, followed optionally by a tfoot element, followed by either zero or more tbody elements or one or more tr elements, followed optionally by a tfoot element (but there can only be one tfoot element child in total).

Content attributes:

Global attributes

orientation

summary

DOM interface:

interface HTMLTableElement : HTMLElement {
           attribute HTMLTableCaptionElement caption;
  HTMLElement createCaption();
  void deleteCaption();
           attribute HTMLTableSectionElement tHead;
  HTMLElement createTHead();
  void deleteTHead();
           attribute HTMLTableSectionElement tFoot;
  HTMLElement createTFoot();
  void deleteTFoot();
  readonly attribute HTMLCollection tBodies;
  HTMLElement createTBody();
  readonly attribute HTMLCollection rows;
  HTMLElement insertRow(in optional long index);
  void deleteRow(in long index);
           attribute DOMString summary;
           attriute DOMString orientation;
};

The table element represents data with more than one dimension, in the form of a table.

Tables must not be used as layout aids. Historically, some Web authors have misused tables in HTML as a way to control their page layout. This usage is non-conforming, because tools attempting to extract tabular data from such documents would obtain very confusing results. In particular, users of accessibility tools like screen readers are likely to find it very difficult to navigate pages with tables used for layout.

There are a variety of alternatives to using HTML tables for layout, primarily using CSS positioning and the CSS table model.

Tables have rows and columns given by their descendants. A table must not have an empty row or column, as described in the description of the table model.

The orientation attribute has cna have the values rows and columns, which indicate whether the table should be read in rows (horizontally), in colums (rows). rows is the default value. Auditory user agents MUST read the table according to this attribute, across rows when it is set to rows and down columns when it is set to columns. User Agents MAY make use of the orientation when splitting tables, such as for small screens or printing.   See the National Braille Association's Tape Recording Manual [http://www.rfbd.org/about.htm] for further explaination of rows and columns.

The status of the summary attribute is an open issue

The summary attribute provides a summary of the table's purpose for user agents rendering to non-visual media such as speech and Braille.

Earlier versions of HTML suggested using summary to provide structural information about the table. This version adds the orientation attribute, and methods on the cell interface that allow user agents to derive that information from the table markup.

Authors SHOULD use summary to provide information that is obvious to visual users of the table, but would be difficult to determine by navigating the table cell by cell in an auditory user agent, and which cannot be derived by the user agent from the markup. The information provided by the summary is needed by users who cannot see the table, but would usually be redundant for those who can.  Authors SHOULD use summary to highlight general idea that is to be drawn from the table, describe trends, high and low points, and the like. When a user with a non-visual user agent encounters a table, the summary should give him enough information to decide if he wishes to explore the table in detail, which can be quite time-consuming.

The information provided by the summary is needed by users who cannot see the table, but would usually be redundant for those who can. For tables where the relationships are not obvious to users who can see the layout, or in other situations where text describing the structure of the table might be useful to sighted users as well as users of screen-readers and Braille devices, it is better to describe the structure using the a caption, legend, or surrounding text instead of, or in addition to, summary. Authors MUST do this in a way that is associated with the table via markup, such that user agents and assistive technology can programmatically determine the relationship. When using summary in combination with another technique, authors MUST NOT duplicate the text, but instead use summary for the parts of the description that are only useful to users who cannot see the table.

User agents MUST expose summary text in the accessibility API on their platform as specified in the Mappings from HTML to Platform APIs document [note: This document is still under development and does not yet have a stable URL. It will have one before last call]. Visual user agents MUST NOT render summary visually in non-editing scenarios, and SHOULD render summary visually in editing scenarios. Non-visual user agents MUST render summary.

Examples:

<table border="1" orientation="row" summary="This table lists the 32 most significant floods
of the 20th Century grouped into 6 types of floods: Regional, flash,
ice-jam, storm-surge, dam-failure, and mudflow. The majority of the
floods (20) are listed as Regional floods. There are between one and
four floods in each of the other 5 categories.  ">

The summary attribute includes the following information:

• A description of the point of the table, that it lists the 32 most significant floods of the 20th century. The number of floods is not included in the caption, as it is easy to see approximately how many there are by looking at the table. The summary is structured as a full sentence, unlike the caption, which is strucutred as a title.
• The grouping into 6 types of floods and a list of the groups.  This type of grouping information can be difficult to understand for a user navigating this markup structure of the table, and is best described in prose.  This information is obvious to visual users of the table.  It can be included in a caption or paragraph under some circumstances.  In a document where the author finds this information redundant, it is better to use summary, so that the information is easily available to users who cannot see the table.
• Highlights the trends that are visible in the talbe. "The majority of the floods (20) are listed as Regional floods. There are between one and
  four floods in each of the other 5 categories." This information is easy to see visually, but much more difficult to find by navigating the structure of the table.li>

The orientation attribute in the row state indicates that the table should be read across.

<caption>Significant Floods of the 20th Century <br />
[M, million; B, billion]</caption>

The caption includes the title of the table, and a key to abbreviations used in the table for Millions and Billions. This information is needed by all users of the table, and so is in the visible caption.

<tbody>
<tr>
<th id="type">Flood Type</th>
<th id="map">Map no.</th>
<th id="date">Date</th>
<th id="area">Area or stream with flooding</th>
<th id="deaths">Reported deaths</th>
<th id="cost">Approximate cost (uninflated)</th>
<th id="comments">Comments</th>
</tr>

TH elements with ID attributes are used to associate cells with their related headers. The cell api has access to these headers

<tr>
<th rowspan="5" id="regional" scope="row">Regional flood</th>
<td headers="regional map">1</td>
<td headers="regional date">Mar.-Apr. 1913</td>
<td headers="regional area">Ohio, statewide</td>
<td headers="regional deaths">467</td>
<td headers="regional cost">$143M</td>
<td headers="regional comments">Excessive regional rain.</td>
</tr>

The first cell in this table is also a TH, and will be available via the cell API.

<tr>
<td headers="regional map">2</td>
<td headers="regional date">Apr.-May 1927</td>
<td headers="regional area">Mississippi River from Missouri to Louisiana</td>
<td headers="regional deaths">unknown</td>
<td headers="regional cost">$230M</td>
<td headers="regional comments">Record discharge downstream from Cairo, Illinois.</td>
</tr>
<tr>
<td headers="regional map">3</td>
<td headers="regional">Mar. 1936</td>
<td headers="regional">New England</td>
<td headers="regional">150+</td>
<td headers="regional">$300M</td>
<td headers="regional">Excessive rainfall on snow.</td>
</tr>
<tr>
<td headers="regional map">4</td>
<td headers="regional">July 1951</td>
<td headers="regional">Kansas and Neosho River Basins in Kansas</td>
<td headers="regional">15</td>
<td headers="regional">$800M</td>
<td headers="regional">Excessive regional rain.</td>
</tr>
<tr>
<td headers="regional map">5</td>
<td headers="regional">Dec. 1964 - Jan. 1965</td>
<td headers="regional">Pacific Northwest</td>
<td headers="regional">47</td>
<td headers="regional">$430M</td>
<td headers="regional">Excessive rainfall on snow.</td>
</tr>
<tr>
<th rowspan="3" scope="row">Flash flood</th>
<td>21</td>
<td>June 14, 1903</td>
<td>Willow Creek in Oregon</td>
<td>225</td>
<td>unknown</td>
<td>City of Heppner, Oregon, destroyed.</td>
</tr>
<tr>
<td>22</td>
<td>June 9-10, 1972</td>
<td>Rapid City, South Dakota</td>
<td>237</td>
<td>$160M</td>
<td>15 inches of rain in 5 hours.</td>
</tr>
<tr>
<td>23</td>
<td>July 31, 1976</td>
<td>Big Thompson and Cache la Poudre Rivers in Colorado</td>
<td>144</td>
<td>$39M</td>
<td>Flash flood in canyon after excessive rainfall.</td>
</tr>
<tr>
<th scope="row">Ice-jam flood</th>
<td>25</td>
<td>May 1992</td>
<td>Yukon River Alaska</td>
<td>0</td>
<td>unknown</td>
<td>100-year flood on Yukon River.</td>
</tr>
<tr>
<th rowspan="2" scope="row">Storm-surge flood</th>
<td>26</td>
<td>Sept. 1990</td>
<td>Galveston, Texas</td>
<td>6,000+</td>
<td>unknown</td>
<td>Hurricane.</td>
</tr>
<tr>
<td>27</td>
<td>Sept. 1938</td>
<td>Northeast United States</td>
<td>494</td>
<td>$360M</td>
<td>Hurricane.</td>
</tr>
<tr>
<th rowspan="2" scope="row">Dam-failure flood</th>
<td>29</td>
<td>Feb. 2, 1972</td>
<td>Buffalo Creek in West Virginia</td>
<td>125</td>
<td>$60M</td>
<td>Dam failure after excessive rainfall.</td>
</tr>
<tr>
<td>30</td>
<td>June 5, 1976</td>
<td>Teton River in Idaho</td>
<td>11</td>
<td>$400M</td>
<td>Earthen dam breached.</td>
</tr>
<tr>
<th scope="row">Mudflow flood</th>
<td>32</td>
<td>May 18, 1980</td>
<td>Toutle and lower Cowlitz Rivers in Washington</td>
<td>60</td>
<td>unknown</td>
<td>Result of eruption of Mt. St. Helens.</td>
</tr>
</tbody>
</table>

The following table has an unusual layout which will not be obvious to many users who can see it. It might benefit from a visible description explaining to the way the table is laid out, something like "Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column". In this case, it is best to describe the table in visible text. The text must be marked up in such a way that assistive technologies can determine programmatically that it is a description for the table.

There are a variety of ways to include this information, such as:

In prose, surrounding the table

<p>In the following table, characteristics are given in the second
column, with the negative side in the left column and the positive
side in the right column.</p>
<table>
 <caption>Characteristics with positive and negative sides</caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

In the table's caption

<table>
 <caption>
  <strong>Characteristics with positive and negative sides.</strong>
  <p>Characteristics are given in the second column, with the
  negative side in the left column and the positive side in the right
  column.</p>
 </caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

In the table's caption, in a details element

<table>
 <caption>
  <strong>Characteristics with positive and negative sides.</strong>
  <details>
   <dt>Help</dt>
   <dd>
    <p>Characteristics are given in the second column, with the
    negative side in the left column and the positive side in the right
    column.</p>
   </dd>
  </details>
 </caption>
 <thead>
  <tr>
   <th id="n"> Negative
   <th> Characteristic
   <th> Positive
 <tbody>
  <tr>
   <td headers="n r1"> Sad
   <th id="r1"> Mood
   <td> Happy
  <tr>
   <td headers="n r2"> Failing
   <th id="r2"> Grade
   <td> Passing
</table>

Next to the table, in the same figure

<figure>
 <dt>Characteristics with positive and negative sides</dt>
 <dd>
  <p>Characteristics are given in the second column, with the
  negative side in the left column and the positive side in the right
  column.</p>
  <table>
   <thead>
    <tr>
     <th id="n"> Negative
     <th> Characteristic
     <th> Positive
   <tbody>
    <tr>
     <td headers="n r1"> Sad
     <th id="r1"> Mood
     <td> Happy
    <tr>
     <td headers="n r2"> Failing
     <th id="r2"> Grade
     <td> Passing
  </table>
 </dd>
</figure>

Next to the table, in a figure's dt

<figure>
 <dt>
  <strong>Characteristics with positive and negative sides</strong>
  <p>Characteristics are given in the second column, with the
  negative side in the left column and the positive side in the right
  column.</p>
 </dt>
 <dd>
  <table>
   <thead>
    <tr>
     <th id="n"> Negative
     <th> Characteristic
     <th> Positive
   <tbody>
    <tr>
     <td headers="n r1"> Sad
     <th id="r1"> Mood
     <td> Happy
    <tr>
     <td headers="n r2"> Failing
     <th id="r2"> Grade
     <td> Passing
  </table>
 </dd>
</figure>

Authors may also use other techniques, or combinations of the above techniques, as appropriate.

The best option, of course, rather than writing a description explaining the way the table is laid out, is to adjust the table such that no explanation is needed.

<table>
 <caption>Characteristics with positive and negative sides</caption>
 <thead>
  <tr>
   <th> Characteristic
   <th> Negative
   <th> Positive
 <tbody>
  <tr>
   <th> Mood
   <td> Sad
   <td> Happy
  <tr>
   <th> Grade
   <td> Failing
   <td> Passing
</table>

table . caption [ = value ]

Returns the table's caption element.

Can be set, to replace the caption element. If the new value is not a caption element, throws a HIERARCHY_REQUEST_ERR exception.

caption = table . createCaption()

Ensures the table has a caption element, and returns it.

table . deleteCaption()

Ensures the table does not have a caption element.

table . tHead [ = value ]

Returns the table's thead element.

Can be set, to replace the thead element. If the new value is not a thead element, throws a HIERARCHY_REQUEST_ERR exception.

thead = table . createTHead()

Ensures the table has a thead element, and returns it.

table . deleteTHead()

Ensures the table does not have a thead element.

table . tFoot [ = value ]

Returns the table's tfoot element.

Can be set, to replace the tfoot element. If the new value is not a tfoot element, throws a HIERARCHY_REQUEST_ERR exception.

tfoot = table . createTFoot()

Ensures the table has a tfoot element, and returns it.

table . deleteTFoot()

Ensures the table does not have a tfoot element.

table . tBodies

Returns an HTMLCollection of the tbody elements of the table.

tbody = table . createTBody()

Creates a tbody element, inserts it into the table, and returns it.

table . rows

Returns an HTMLCollection of the tr elements of the table.

tr = table . insertRow(index)

Creates a tr element, along with a tbody if required, inserts them into the table at the position given by the argument, and returns the tr.

The position is relative to the rows in the table. The index −1 is equivalent to inserting at the end of the table.

If the given position is less than −1 or greater than the number of rows, throws an INDEX_SIZE_ERR exception.

table . deleteRow(index)

Removes the tr element with the given position in the table.

The position is relative to the rows in the table. The index −1 is equivalent to deleting the last row of the table.

If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an INDEX_SIZE_ERR exception.

4.9.2 The caption element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As the first element child of a table element.

Content model:

Flow content, but with no descendant table elements.

Content attributes:

Global attributes

DOM interface:

interface HTMLTableCaptionElement : HTMLElement {};

The caption element represents the title of the table that is its parent, if it has a parent and that is a table element.

When a table element is the only content in a figure element's dd, the caption element should be omitted in favor of the dt.

A caption can introduce context for a table, making it significantly easier to understand.

<caption>
<p>Table 1.
<p>This table shows the total score obtained from rolling two
six-sided dice. The first row represents the value of the first die,
the first column the value of the second die. The total is given in
the cell that corresponds to the values of the two dice.
</caption>

4.9.3 The colgroup element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a table element, after any caption elements and before any thead, tbody, tfoot, and tr elements.

Content model:

Zero or more col elements.

Content attributes:

Global attributes

span

DOM interface:

interface HTMLTableColElement : HTMLElement {
           attribute unsigned long span;
};

The colgroup element represents a group of one or more columns in the table that is its parent, if it has a parent and that is a table element.

If the colgroup element contains no col elements, then the element may have a span content attribute specified, whose value must be a valid non-negative integer greater than zero.

4.9.4 The col element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a colgroup element that doesn't have a span attribute.

Content model:

Empty.

Content attributes:

Global attributes

span

DOM interface:

HTMLTableColElement, same as for colgroup elements. This interface defines one member, span.

If a col element has a parent and that is a colgroup element that itself has a parent that is a table element, then the col element represents one or more columns in the column group represented by that colgroup.

The element may have a span content attribute specified, whose value must be a valid non-negative integer greater than zero.

4.9.5 The tbody element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a table element, after any caption, colgroup, and thead elements, but only if there are no tr elements that are children of the table element.

Content model:

Zero or more tr elements

Content attributes:

Global attributes

DOM interface:

interface HTMLTableSectionElement : HTMLElement {
  readonly attribute HTMLCollection rows;
  HTMLElement insertRow(in optional long index);
  void deleteRow(in long index);
};

The HTMLTableSectionElement interface is also used for thead and tfoot elements.

The tbody element represents a block of rows that consist of a body of data for the parent table element, if the tbody element has a parent and it is a table.

tbody . rows

Returns an HTMLCollection of the tr elements of the table section.

tr = tbody . insertRow( [ index ] )

Creates a tr element, inserts it into the table section at the position given by the argument, and returns the tr.

The position is relative to the rows in the table section. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table section.

If the given position is less than −1 or greater than the number of rows, throws an INDEX_SIZE_ERR exception.

tbody . deleteRow(index)

Removes the tr element with the given position in the table section.

The position is relative to the rows in the table section. The index −1 is equivalent to deleting the last row of the table section.

If the given position is less than −1 or greater than the index of the last row, or if there are no rows, throws an INDEX_SIZE_ERR exception.

4.9.6 The thead element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a table element, after any caption, and colgroup elements and before any tbody, tfoot, and tr elements, but only if there are no other thead elements that are children of the table element.

Content model:

Zero or more tr elements

Content attributes:

Global attributes

DOM interface:

HTMLTableSectionElement, as defined for tbody elements.

The thead element represents the block of rows that consist of the column labels (headers) for the parent table element, if the thead element has a parent and it is a table.

4.9.7 The tfoot element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a table element, after any caption, colgroup, and thead elements and before any tbody and tr elements, but only if there are no other tfoot elements that are children of the table element.

As a child of a table element, after any caption, colgroup, thead, tbody, and tr elements, but only if there are no other tfoot elements that are children of the table element.

Content model:

Zero or more tr elements

Content attributes:

Global attributes

DOM interface:

HTMLTableSectionElement, as defined for tbody elements.

The tfoot element represents the block of rows that consist of the column summaries (footers) for the parent table element, if the tfoot element has a parent and it is a table.

4.9.8 The tr element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a thead element.

As a child of a tbody element.

As a child of a tfoot element.

As a child of a table element, after any caption, colgroup, and thead elements, but only if there are no tbody elements that are children of the table element.

Content model:

When the parent node is a thead element: Zero or more th elements

Otherwise: Zero or more td or th elements

Content attributes:

Global attributes

DOM interface:

interface HTMLTableRowElement : HTMLElement {
  readonly attribute long rowIndex;
  readonly attribute long sectionRowIndex;
  readonly attribute HTMLCollection cells;
  HTMLElement insertCell(in optional long index);
  void deleteCell(in long index);
};

The tr element represents a row of cells in a table.

tr . rowIndex

Returns the position of the row in the table's rows list.

Returns −1 if the element isn't in a table.

tr . sectionRowIndex

Returns the position of the row in the table section's rows list.

Returns −1 if the element isn't in a table section.

tr . cells

Returns an HTMLCollection of the td and th elements of the row.

cell = tr . insertCell( [ index ] )

Creates a td element, inserts it into the table row at the position given by the argument, and returns the td.

The position is relative to the cells in the row. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the row.

If the given position is less than −1 or greater than the number of cells, throws an INDEX_SIZE_ERR exception.

tr . deleteCell(index)

Removes the td or th element with the given position in the row.

The position is relative to the cells in the row. The index −1 is equivalent to deleting the last cell of the row.

If the given position is less than −1 or greater than the index of the last cell, or if there are no cells, throws an INDEX_SIZE_ERR exception.

4.9.9 The td element

Status: Last call for comments

Categories

Sectioning root.

Contexts in which this element may be used:

As a child of a tr element.

Content model:

Flow content.

Content attributes:

Global attributes

colspan

rowspan

headers

DOM interface:

interface HTMLTableDataCellElement : HTMLTableCellElement {};

The td element represents a data cell in a table.

4.9.10 The th element

Status: Last call for comments

Categories

None.

Contexts in which this element may be used:

As a child of a tr element.

Content model:

Phrasing content.

Content attributes:

Global attributes

colspan

rowspan

headers

scope

DOM interface:

interface HTMLTableHeaderCellElement : HTMLTableCellElement {
           attribute DOMString scope;
};

The th element represents a header cell in a table.

The th element may have a scope content attribute specified. The scope attribute is an enumerated attribute with five states, four of which have explicit keywords:

The row keyword, which maps to the row state

The row state means the header cell applies to some of the subsequent cells in the same row(s).

The col keyword, which maps to the column state

The column state means the header cell applies to some of the subsequent cells in the same column(s).

The rowgroup keyword, which maps to the row group state

The row group state means the header cell applies to all the remaining cells in the row group. A th element's scope attribute must not be in the row group state if the element is not anchored in a row group.

The colgroup keyword, which maps to the column group state

The column group state means the header cell applies to all the remaining cells in the column group. A th element's scope attribute must not be in the column group state if the element is not anchored in a column group.

The auto state

The auto state makes the header cell apply to a set of cells selected based on context.

The scope attribute's missing value default is the auto state.

The following example shows how the scope attribute's rowgroup value affects which data cells a header cell applies to.

Here is a markup fragment showing a table:

<table>
 <thead>
  <tr> <th> ID <th> Measurement <th> Average <th> Maximum
 <tbody>
  <tr> <td> <th scope=rowgroup> Cats <td> <td>
  <tr> <td> 93 <th> Legs <td> 3.5 <td> 4
  <tr> <td> 10 <th> Tails <td> 1 <td> 1
 <tbody>
  <tr> <td> <th scope=rowgroup> English speakers <td> <td>
  <tr> <td> 32 <th> Legs <td> 2.67 <td> 4
  <tr> <td> 35 <th> Tails <td> 0.33 <td> 1
</table>

This would result in the following table:

ID	Measurement	Average	Maximum
	Cats
93	Legs	3.5	4
10	Tails	1	1
	English speakers
32	Legs	2.67	4
35	Tails	0.33	1

The headers in the first row all apply directly down to the rows in their column.

The headers with the explicit scope attributes apply to all the cells in their row group other than the cells in the first column.

The remaining headers apply just to the cells to the right of them.

4.9.11 Attributes common to td and th elements

Status: Last call for comments

The td and th elements may have a colspan content attribute specified, whose value must be a valid non-negative integer greater than zero.

The td and th elements may also have a rowspan content attribute specified, whose value must be a valid non-negative integer.

These attributes give the number of columns and rows respectively that the cell is to span. These attributes must not be used to overlap cells, as described in the description of the table model.

The td and th element may have a headers content attribute specified. The headers attribute, if specified, must contain a string consisting of an unordered set of unique space-separated tokens, each of which must have the value of an ID of a th element taking part in the same table as the td or th element (as defined by the table model).

A th element with ID id is said to be directly targeted by all td and th elements in the same table that have headers attributes whose values include as one of their tokens the ID id. A th element A is said to be targeted by a th or td element B if either A is directly targeted by B or if there exists an element C that is itself targeted by the element B and A is directly targeted by C.

A th element must not be targeted by itself.

The td and th elements implement interfaces that inherit from the HTMLTableCellElement interface:

interface HTMLTableCellElement : HTMLElement {
           attribute unsigned long colSpan;
           attribute unsigned long rowSpan;
           attribute DOMString headers;
  readonly attribute long cellIndex;
};

cell . cellIndex

Returns the position of the cell in the row's cells list.

Returns 0 if the element isn't in a row.

cell . cellColumnHeaders

Returns an HTMLCollection of column headers associated with this cell.

cell . cellColumnGroupHeaders

Returns an HTMLCollection of column group headers associated with this cell.

cell . cellRowHeaders

Returns an HTMLCollection of row headers associated with this cell.

cell . cellRowGroupHeaders

Returns an HTMLCollection of row group headers associated with this cell.

QUESTION:  are there implied row groups and col groups based on rowspan and colspan on th?  Should there be?

4.9.13 Examples

Status: Last call for comments

This section is non-normative.

The following shows how might one mark up the bottom part of table 45 of the Smithsonian physical tables, Volume 71:

<table>
 <caption>Specification values: <b>Steel</b>, <b>Castings</b>,
 Ann. A.S.T.M. A27-16, Class B;* P max. 0.06; S max. 0.05.</caption>
 <thead>
  <tr>
   <th rowspan=2>Grade.</th>
   <th rowspan=2>Yield Point.</th>
   <th colspan=2>Ultimate tensile strength</th>
   <th rowspan=2>Per sent elong. 50.8mm or 2 in.</th>
   <th rowspan=2>Per cent reduct. area.</th>
  </tr>
  <tr>
   <th>kg/mm<sup>2</sup></th>
   <th>lb/in<sup>2</sup></th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>Hard</td>
   <td>0.45 ultimate</td>
   <td>56.2</td>
   <td>80,000</td>
   <td>15</td>
   <td>20</td>
  </tr>
  <tr>
   <td>Medium</td>
   <td>0.45 ultimate</td>
   <td>49.2</td>
   <td>70,000</td>
   <td>18</td>
   <td>25</td>
  </tr>
  <tr>
   <td>Soft</td>
   <td>0.45 ultimate</td>
   <td>42.2</td>
   <td>60,000</td>
   <td>22</td>
   <td>30</td>
  </tr>
 </tbody>
</table>

This table could look like this:

The following shows how one might mark up the gross margin table on page 46 of Apple, Inc's 10-K filing for fiscal year 2008:

<table>
 <thead>
  <tr>
   <th>
   <th>2008
   <th>2007
   <th>2006
 <tbody>
  <tr>
   <th>Net sales
   <td>$ 32,479
   <td>$ 24,006
   <td>$ 19,315
  <tr>
   <th>Cost of sales
   <td>  21,334
   <td>  15,852
   <td>  13,717
 <tbody>
  <tr>
   <th>Gross margin
   <td>$ 11,145
   <td>$  8,154
   <td>$  5,598
 <tfoot>
  <tr>
   <th>Gross margin percentage
   <td>34.3%
   <td>34.0%
   <td>29.0%
</table>

This table could look like this:

The following shows how one might mark up the operating expenses table from lower on the same page of that document:

<table>
 <colgroup> <col>
 <colgroup> <col> <col> <col>
 <thead>
  <tr> <th> <th>2008 <th>2007 <th>2006
 <tbody>
  <tr> <th scope=rowgroup> Research and development
       <td> $ 1,109 <td> $ 782 <td> $ 712 
  <tr> <th scope=row> Percentage of net sales
       <td> 3.4% <td> 3.3% <td> 3.7% 
 <tbody>
  <tr> <th scope=rowgroup> Selling, general, and administrative
       <td> $ 3,761 <td> $ 2,963 <td> $ 2,433 
  <tr> <th scope=row> Percentage of net sales
       <td> 11.6% <td> 12.3% <td> 12.6%
</table>

This table could look like this:

4.10 Forms

Status: Last call for comments

Forms allow unscripted client-server interaction: given a form, a user can provide data, submit it to the server, and have the server act on it accordingly (e.g. returning the results of a search or calculation). The elements used in forms can also be used for user interaction with no associated submission mechanism, in conjunction with scripts.

Mostly for historical reasons, elements in this section fall into several overlapping (but subtly different) categories in addition to the usual ones like flow content, phrasing content, and interactive content.

A number of the elements are form-associated elements, which means they can have a form owner and, to expose this, have a form content attribute with a matching form IDL attribute.

• button
• fieldset
• input
• keygen
• label
• object
• output
• select
• textarea

The form-associated elements fall into several subcategories:

Listed

Denotes elements that are listed in the form.elements and fieldset.elements APIs.

• button
• fieldset
• input
• keygen
• object
• output
• select
• textarea

Labelable

Denotes elements that can be associated with label elements.

• button
• input
• keygen
• select
• textarea

Submittable elements

Denotes elements that can be used for constructing the form data set when a form element is submitted.

• button
• input
• keygen
• object
• select
• textarea

Resettable elements

Denotes elements that can be affected when a form element is reset.

• input
• keygen
• output
• select
• textarea

In addition, some submittable elements can be, depending on their attributes, buttons. The prose below defines when an element is a button. Some buttons are specifically submit buttons.

The object element is also a form-associated element and can, with the use of a suitable plugin, partake in form submission.