</TABLE>
<P>
All non-printing characters such as tabs or newlines are ignored.
Above, a <I>string</I> is any collection of printable characters, including
spaces. For tables, outside of the body of a &lt;TD&gt; element, 
whitespace characters are ignored, including spaces; within a &lt;TD&gt; element, spaces
are preserved but all other white space characters are discarded.
<B>N.B.</B> For technical reasons, if a table is wrapped in a font element such as  &lt;FONT&gt;
or  &lt;B&gt;, any space immediately before or after this will cause a syntax error. For example,
the label
<PRE>
&lt; &lt;U&gt;&lt;TABLE&gt;&lt;TR&gt;&lt;TD&gt;a&lt;/TD&gt;&lt;/TR&gt;&lt;/U&gt;&gt;
</PRE>
is not legal. Removing either the space or the &lt;U&gt...&lt;/U&gt will fix this.
<P>
HTML comments are allowed within an HTML string. They can occur anywhere
provided that, if they contain part of an HTML element, they must contain
the entire element.
<P>
As is obvious from the above description, the interpretation of white space
characters is one place where HTML-like labels is very different from 
standard HTML. In HTML, any sequence of white space characters is 
collapsed to a single space, If the user does not want this to happen, the
input must use non-breaking spaces "&amp;nbsp;". This makes sense in
HTML, where text layout depends dynamically on the space available. In
Graphviz, the layout is statically determined by the input, so it is
reasonable to treat ordinary space characters as non-breaking. In addition,
ignoring tabs and newlines allows the input text to be formatted for
easier reading. 
<P>
Each of the HTML elements has a set of optional attributes.
Attribute values must appear in double quotes.
<P>
  &lt;!-- Table element --&gt;
<PRE>
&lt;TABLE
  ALIGN="CENTER|LEFT|RIGHT"
  BGCOLOR="<I>color</I>"
  BORDER="<I>value</I>"
  CELLBORDER="<I>value</I>"
  CELLPADDING="<I>value</I>"
  CELLSPACING="<I>value</I>"
  COLOR="<I>color</I>"
  COLUMNS="<I>value</I>"
  FIXEDSIZE="FALSE|TRUE"
  GRADIENTANGLE="<I>value</I>"
  HEIGHT="<I>value</I>"
  HREF="<I>value</I>"
  ID="<I>value</I>"
  PORT="<I>portName</I>"
  ROWS="<I>value</I>"
  SIDES="<I>value</I>"
  STYLE="<I>value</I>"
  TARGET="<I>value</I>"
  TITLE="<I>value</I>"
  TOOLTIP="<I>value</I>"
  VALIGN="MIDDLE|BOTTOM|TOP"
  WIDTH="<I>value</I>"
&gt;
</PRE>
<P>
  &lt;!-- Table row --&gt;
<PRE>&lt;TR
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Table cell --&gt;
<PRE>&lt;TD
  ALIGN="CENTER|LEFT|RIGHT|TEXT"
  BALIGN="CENTER|LEFT|RIGHT"
  BGCOLOR="<I>color</I>"
  BORDER="<I>value</I>"
  CELLPADDING="<I>value</I>"
  CELLSPACING="<I>value</I>"
  COLOR="<I>color</I>"
  COLSPAN="<I>value</I>"
  FIXEDSIZE="FALSE|TRUE"
  GRADIENTANGLE="<I>value</I>"
  HEIGHT="<I>value</I>"
  HREF="<I>value</I>"
  ID="<I>value</I>"
  PORT="<I>portName</I>"
  ROWSPAN="<I>value</I>"
  SIDES="<I>value</I>"
  STYLE="<I>value</I>"
  TARGET="<I>value</I>"
  TITLE="<I>value</I>"
  TOOLTIP="<I>value</I>"
  VALIGN="MIDDLE|BOTTOM|TOP"
  WIDTH="<I>value</I>"
&gt;
</PRE>

<P>
  &lt;!-- Font specification --&gt;
<PRE>&lt;FONT
  COLOR="<I>color</I>"
  FACE="<I>fontname</I>"
  POINT-SIZE="<I>value</I>"
&gt;
</PRE>

<P>
  &lt;!-- Line break --&gt;
<PRE>&lt;BR
  ALIGN="CENTER|LEFT|RIGHT"
/&gt;
</PRE>

<P>
  &lt;!-- Image inclusion --&gt;
<PRE>&lt;IMG
  SCALE="FALSE|TRUE|WIDTH|HEIGHT|BOTH"
  SRC="<I>value</I>"
/&gt;
</PRE>
<P>
  &lt;!-- Italic style --&gt;
<PRE>&lt;I
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Bold style --&gt;
<PRE>&lt;B
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Underline text --&gt;
<PRE>&lt;U
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Overline text --&gt;
<PRE>&lt;O
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Subscript text --&gt;
<PRE>&lt;SUB
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Superscript text --&gt;
<PRE>&lt;SUP
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Strike-through text --&gt;
<PRE>&lt;S
  &lt;!-- No attributes --&gt;
&gt;
</PRE>
<P>
  &lt;!-- Horizontal rule --&gt;
<PRE>&lt;HR
  &lt;!-- No attributes --&gt;
/&gt;
</PRE>
<P>
  &lt;!-- Vertical rule --&gt;
<PRE>&lt;VR
  &lt;!-- No attributes --&gt;
/&gt;
</PRE>

<P>
<B><I><FONT SIZE=-1>ALIGN</FONT> </I></B>
<BLOCKQUOTE>
specifies horizontal placement. When an object is allocated
more space than required, this value determines where the extra space
is placed left and right of the object.
<P>
<ul>
<LI>CENTER aligns the object in the center. (Default) </LI>
<LI>LEFT aligns the object on the left.</LI>
<LI>RIGHT aligns the object on the right.  </LI>
<LI>(<T>&lt;TD&gt;</T> only) TEXT aligns lines of text using the full
cell width. The alignment of a line is determined by its (possibly
implicit) associated <T>&lt;BR&gt;</T> element.</LI> 
</ul>
<P>
The contents of a cell are normally aligned as a block. In particular,
lines of text are first aligned as a text block based on the width of
the widest line and the corresponding <T>&lt;BR&gt;</T> elements. Then,
the entire text block is aligned within a cell. If, however, the
cell's <B><I>ALIGN</I></B> value is <T>"TEXT"</T>, and the cell contains
lines of text, then the lines are justified using the entire available
width of the cell. If the cell does not contain text, then the contained
image or table is centered.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>BALIGN</FONT> </I></B>
<BLOCKQUOTE>
specifies the default alignment of <T>&lt;BR&gt;</T> elements contained
in the cell. That is, if a <T>&lt;BR&gt;</T> element has no
explicit <B><I>ALIGN</I></B> attribute, the attribute value is specified
by the value of <B><I>BALIGN</I></B>.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>BGCOLOR="color"</FONT></I></B>
<BLOCKQUOTE>
sets the color of the background. This color can be 
overridden by a <B><I>BGCOLOR</I></B> attribute in descendents.
The value can be a single color or two colors separated by a colon, the
latter indicating a gradient fill.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>BORDER="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the width of the border around the object in points.
A value of zero indicates no border. The default is 1.
The maximum value is 255.
If set in a table, and <B><I>CELLBORDER</I></B> is not set,
this value is also used for all cells in the table.
It can be overridden by a <B><I>BORDER</I></B> tag in  a cell.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>CELLBORDER="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the width of the border for all cells in a table.
It can be overridden by a <B><I>BORDER</I></B> tag in  a cell.
The maximum value is 255.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>CELLPADDING="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the space, in points, between a cell's border and its content.
The default is 2.
The maximum value is 255.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>CELLSPACING="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the space, in points, between cells in a table and between
a cell and the table's border.  The default is 2.
The maximum value is 127.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>COLOR="color"</FONT></I></B>
<BLOCKQUOTE>
sets the color of the font within the scope of
&lt;FONT&gt;...&lt;/FONT&gt;, or the border color
of the table or cell within the scope of
&lt;TABLE&gt;...&lt;/TABLE&gt;,
or &lt;TD&gt;...&lt;/TD&gt;.
This color can be 
overridden by a <B><I>COLOR</I></B> attribute in descendents.
By default, the font color is determined by the
<A HREF="attrs.html#d:fontcolor">fontcolor</A> attribute of
the corresponding node, edge or graph, and the border color
is determined by the
<A HREF="attrs.html#d:color">color</A> attribute of
the corresponding node, edge or graph.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>COLSPAN="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the number of columns spanned by the cell. The default is 1.
The maximum value is 65535.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>COLUMNS="value"</FONT></I></B>
<BLOCKQUOTE>
provides general formatting information concerning the columns.
At present, the only legal value is "*", which causes a vertical rule to
appear between every cell in every row.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>FACE="fontname"</FONT></I></B>
<BLOCKQUOTE>
specifies the font to use within the scope of
&lt;FONT&gt;...&lt;/FONT&gt;.
This can be 
overridden by a <B><I>FACE</I></B> attribute in descendents.
By default, the font name is determined by the
<A HREF="attrs.html#d:fontname">fontname</A> attribute of the corresponding
node, edge or graph.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>FIXEDSIZE</FONT> </I></B>
<BLOCKQUOTE>
specifies whether the values given by the <B><I>WIDTH</I></B> 
and <B><I>HEIGHT</I></B> attributes are enforced.
<P>
<ul>
<LI>FALSE allows the object to grow so that all its contents will fit. (Default) </LI>
<LI>TRUE fixes the object size to its given <B><I>WIDTH</I></B> 
and <B><I>HEIGHT</I></B>.
Both of these attributes must be supplied.</LI>
</ul>
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>GRADIENTANGLE="value"</FONT></I></B>
<BLOCKQUOTE>
gives the angle used in a gradient fill if the 
<B><I>BGCOLOR</I></B> is a color list. For the default linear gradient,
this specifies 
the angle of a line through the center along which the colors transform.
Thus, an angle of 0 will cause a left-to-right progression.
For radial gradients (see <B><I>STYLE</I></B>), the angle specifies the position
of the center of the coloring. An angle of 0 places the center at the center of the
table or cell; an non-zero angle places the fill center along that angle near the
boundary.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>HEIGHT="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the mininum height, in points, of the object. The height
includes the contents, any spacing and the border. Unless
<B><I>FIXEDSIZE</I></B> is true, the height will be expanded to allow
the contents to fit.
The maximum value is 65535.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>HREF="value"</FONT></I></B>
<BLOCKQUOTE>
attaches a URL to the object.
Note that the <TT>"value"</TT> is treated as an
<A HREF=attrs.html#k:escString>escString</A> similarly to the
<A HREF=attrs.html#d:URL>URL</A> attribute.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>ID="value"</FONT></I></B>
<BLOCKQUOTE>
allows the user to specify a unique ID for a table or cell. See
the <A HREF=attrs.html#d:id>id</A> attribute for more information.
Note that the <TT>"value"</TT> is treated as an
<A HREF=attrs.html#k:escString>escString</A> similarly to the
<A HREF=attrs.html#d:id>id</A> attribute.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>POINT-SIZE="value"</FONT></I></B>
<BLOCKQUOTE>
sets the size of the font, in points, used within the scope of
&lt;FONT&gt;...&lt;/FONT&gt;.
This can be 
overridden by a <B><I>POINT-SIZE</I></B> attribute in descendents.
By default, the font size is determined by the
<A HREF="attrs.html#d:fontsize">fontsize</A> attribute of the corresponding
node, edge or graph.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>PORT="value"</FONT></I></B>
<BLOCKQUOTE>
attaches a portname to the object.
(See <A HREF=attrs.html#k:portPos>portPos</A>.)
This can be used to modify the head
or tail of an edge, so that the end attaches directly to the object.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>ROWS="value"</FONT></I></B>
<BLOCKQUOTE>
provides general formatting information concerning the rows.
At present, the only legal value is "*", which causes a horizontal rule to
appear between every row.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>ROWSPAN="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the number of rows spanned by the cell. The default is 1.
The maximum value is 65535.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>SCALE</FONT></I></B>
<BLOCKQUOTE>
specifies how an image will use any extra space available in its cell.
Allowed values are
<ul>
<LI>FALSE : keep image its natural size. (Default) </LI>
<LI>TRUE : scale image uniformly to fit.</LI>
<LI>WIDTH : expand image width to fill  </LI>
<LI>HEIGHT : expand image height to fill  </LI>
<LI>BOTH : expand both image width height to fill  </LI>
</ul>
If this attribute is undefined, 
the image inherits the <A HREF="attrs.html#d:imagescale">imagescale</A> 
attribute of the graph object being drawn.
As with the <A HREF="attrs.html#d:imagescale">imagescale</A>
attribute, if the cell has a fixed size and the image is too large,
any offending dimension will be shrunk to fit the space, the
scaling being uniform in width and height if <I>SCALE=<TT>"true"</TT></I>.
Note that the containing cell's <B><I>ALIGN</I></B> 
and <B><I>VALIGN</I></B> attributes override
an image's <B><I>SCALE</I></B> attribute.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>SIDES="value"</FONT></I></B>
<BLOCKQUOTE>
specifies which sides of a border in a cell or table should be drawn, if
a border is drawn. By default, all sides are drawn. The <TT>"value"</TT>
string can contain any collection of the (case-insensitive) 
characters <TT>'L'</TT>, <TT>'T'</TT>, <TT>'R'</TT>, or <TT>'B'</TT>,
corresponding to the left, top, right and, bottom sides of the border,
respectively. For example, <TT>SIDES="LB"</TT> would indicate only the
left and bottom segments of the  border should be drawn.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>SRC="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the image file to be displayed in the cell.
Note that if the software is used as a web server, file system access
to images is more restricted. See <A HREF="command.html#d:GV_FILE_PATH">GV_FILE_PATH</A>
and <A HREF="command.html#d:SERVER_NAME">SERVER_NAME</A>.
</BLOCKQUOTE>

<P>
<B><I><FONT SIZE=-1>STYLE</FONT> </I></B>
<BLOCKQUOTE>
specifies style characteristics of the table or cell. Style characteristics are
given as a comma or space separated list of style attributes. At present, the only
legal attributes are "ROUNDED" and "RADIAL" for tables, and "RADIAL" for cells.
If "ROUNDED" is specified, the table will have rounded corners.
This probably works best if the outmost cells have no borders, or their CELLSPACING
is sufficiently large.
If it is desirable to have borders around the cells, use <I><B>HR</B></I>
and <I><B>VR</B></I> elements, or the <I><B>COLUMNS</B></I> and <I><B>ROWS</B></I> attributes of <I><B>TABLE</B></I>.
<P>
The "RADIAL" attribute indicates a radial gradient fill. See the <B><I>BGCOLOR</I></B> and
<B><I>GRADIENTANGLE</I></B> attributes.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>TARGET="value"</FONT></I></B>
<BLOCKQUOTE>
determines which window of the browser is used for the URL if the object 
has one. 
See <A HREF="http://www.w3.org/TR/html401/present/frames.html#adef-target">W3C documentation</A>.
Note that the <TT>"value"</TT> is treated as an
<A HREF=attrs.html#k:escString>escString</A> similarly to the
<A HREF=attrs.html#d:target>target</A> attribute.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>TITLE="value"</FONT></I></B>
<BLOCKQUOTE>
sets the tooltip annotation attached to the element. 
This is used only if the element has a HREF attribute.
Note that the <TT>"value"</TT> is treated as an
<A HREF=attrs.html#k:escString>escString</A> similarly to the
<A HREF=attrs.html#d:tooltip>tooltip</A> attribute.
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>TOOLTIP="value"</FONT></I></B>
<BLOCKQUOTE>
is an alias for <B><I><FONT SIZE=-1>TITLE</FONT></I></B>.
</BLOCKQUOTE>

<P>
<B><I><FONT SIZE=-1>VALIGN</FONT> </I></B>
<BLOCKQUOTE>
specifies vertical placement. When an object is allocated
more space than required, this value determines where the extra space
is placed above and below the object.
<P>
<ul>
<LI>MIDDLE aligns the object in the center. (Default) </LI>
<LI>BOTTOM aligns the object on the bottom.</LI>
<LI>TOP aligns the object on the top.  </LI>
</ul>
</BLOCKQUOTE>

<B><I><FONT SIZE=-1>WIDTH="value"</FONT></I></B>
<BLOCKQUOTE>
specifies the mininum width, in points, of the object. The width
includes the contents, any spacing and the border. Unless
<B><I>FIXEDSIZE</I></B> is true, the width will be expanded to allow
the contents to fit.
The maximum value is 65535.
</BLOCKQUOTE>

<P>
There is some inheritance among the attributes. If a table specifies
a <I><B>CELLPADDING</B></I>, <I><B>CELLBORDER</B></I> or <I><B>BORDER</B></I> 
value, this value is used by the table's
cells unless overridden. If a cell or table specifies a <I><B>BGCOLOR</B></I>,
this will be the background color for all of its descendents.
Of course, if a background or fill color is specified for the
graph object owning the label, this will be the original
background for the label.
The object's fontname, fontcolor and fontsize attributes
are the default for drawing text. These can be overridden by using
<I><B>FONT</B></I> to set new values. The new font values will hold
until overridden by an enclosed <I><B>FONT</B></I> element.
Finally, the pencolor or color of the graph object will be used as
the border color.
<P>
If you want horizontal or vertical rules used uniformly within a table, consider
using the <I><B>COLUMNS</B></I> or <I><B>ROWS</B></I> attributes 
rather than using many
<I><B>HR</B></I> and <I><B>VR</B></I> elements.
<P>
Because of certain limitations in handling tables in a device-independent
manner, when <I><B>BORDER</B></I> is 1 and both table and cell borders
are on and <I><B>CELLSPACING</B></I> is less than 2, anomalies can arise
in the output, such as gaps between sides of borders which should be
abutting or even collinear. The user can usual get around this by increasing
the border size or the spacing, or turning off the table border.
<P>
As an example of HTML labels, the dot input 
<XMP>
