Basic HTML formatting tags

© Mike Smith M.A.Smith at brighton dot ac dot uk University of Brighton UK.

Contents
* Introduction to HTML
* Simple formatting tags
* Colour
* Specifying a colour by name
* Specifying a colour by RGB value
* Colours for text, links, etc.
* Logical formatting tags
* Paragraph and line breaks
* Headings and rulers
* Insertion of in-line images
* A background image
* Creating a list of items
* Hyper text links
- URL
* Tables
- Single cell
- Row(s) of cells
- Heading to a column
- Spanning rows and columns
- Colouring table cells
* Using HTML Special characters
* Literal copy and centering of text
* Inserting an e-mail address
* Redirect to new page


Warning if you are not using a browser that supports tables
such as Netscape 1.1 or later then this page
will probably be very difficult to read.

 

Index Introduction to HTML

HTML (HyperText Markup Language) is a markup language which consists of tags embedded in the text of a document. The browser reading the document interprets these markup tags to help format the document for subsequent display to a reader. However, many of the decisions about layout are made by the browser. Remember, web browsers are available for a wide variety of computer systems.

The browser thus displays the document with regard to features that the viewer selects either explicitly or implicitly. Factors affecting the layout and presentation include:

The browser, ignores extra spaces and new lines between words and markup tags when reading the document. Thus, the following three text fragments will be formatted identically.

Fragment 1 Fragment 2 Fragment 3
The browser will ignore
new lines and extra
spaces in the text.
The browser will
ignore new lines and
extra spaces in the text.
The browser will
ignore new lines and
extra    spaces in the text.

to produce the following:

The browser will ignore new lines and extra spaces in the text.

Try it

 

The markup language is made up of tags such as <B> which requests text that follows to be in bold type. This bolding is turned off by the inverse markup tag </B>.

In writing a tag, the case of the letters in the tag name is unimportant so that <B> and <b> represent the same tag.

The basic layout of an HTML document and the resultant information displayed by a browser such as Netscape is shown below:

Displayed by browser HTML markup required
An example of a simple web page.
 <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
 <HTML>

  <HEAD>
   <TITLE>Title of the web page </TITLE>
  </HEAD>

  <BODY>
  An example of a simple
  <B>web</B>
  page.
  </BODY>

 </HTML>
 

The tags used are:

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML //EN">
Informs the browser that this is an HTML document. This is an SGML tag to identify the version of HTML being used, in this case just HTML. Version 3.2 browsers (e.g. Netscape) are happy about this pretense that this document is just plain HTML.
<HTML> </HTML>
Defines the extent of the HTML markup text
<HEAD> </HEAD>
Contains descriptions of the HTML page. This meta information is not displayed as part of the web page.
<TITLE> </TITLE>
Describes the title of the page. This description is usually displayed by the browser as the title of the window in which the web page is displayed. This information is also used by some search engines to compile an index of web pages.
<BODY> </BODY>
Delimits the body of the web page. In the body is the text to be displayed as well as HTML markup tags to hint at the format of the text.
<B> </B>
Displays the enclosed text in a bold typeface.

Note:
The tags can be written in upper-case or a mixture of upper- and lower-case or just lower-case. For example, <HTML>, <HtMl> and <html> all represent the same tag.

 

IndexSimple formatting tags

The following are some of the simple formatting tags available in HTML.

Formatted text HTML markup required
The text is bolded.

 The <B>text</B> is bolded.
 
The text is italicized.

 The <I>text</I> is italicized.
 
The text is in a teletype font.

 The <TT>text</TT> is in a teletype font.
 
The text is 2 sizes larger and the text is in red. The size attribute may also be an absolute value in the range 1 .. 7.

 The <FONT SIZE="+2" COLOR="RED">text</FONT>
 is 2 sizes larger and the text is in red.
 The size attribute may also
 be an absolute value in the range 1 .. 7.
 
Use the e-mail address
M.A.Smith at brighton dot ac dot uk
to contact me.

 Use the e-mail address
 <ADDRESS>M.A.Smith at brighton dot ac dot uk</ADDRESS>
 to contact me.
 

Note:
How the formatting is turned off by the inverse of the HTML formatting tag.

Try it

 

Index Colour

The following are some of the formatting tags available in HTML to specify colour in a document.

Index Specifying a colour by name

The formatting tag <FONT> with the attribute COLOR="red" is used to change selectively the colour of the text of the document to red. This temporary colour change terminates on the </FONT> tag.

Formatted text HTML markup required
* Red* Green* Blue*
 *
 <FONT COLOR="red">Red</FONT>*
 <FONT COLOR="green">Green</FONT>*
 <FONT COLOR="blue">Blue</FONT>*
 

Possible values for a named colour are: black [###], maroon [###], green [###], olive [###], navy [###], purple [###], teal [###], gray [###], silver [###], red [###], lime [###], yellow [###], blue [###], fuchsia [###], aqua [###], white [###].

Try it

Index Specifying a colour by RGB value

A general colour is specified in terms of the three primary colours red, blue and green. Each primary colour is defined as a two digit Hexadecimal number that representing the strength of that primary colour.

In this specification hexadecimal 00 means 0% of the colour and hexadecimal FF means 100% of the colour.

For example, to specify red the hexadecimal number FF0000 is used. In this number:

Formatted text HTML markup required
* Red* Green* Blue*
 *
 <FONT COLOR="#FF0000">Red</FONT>*
 <FONT COLOR="#00FF00">Green</FONT>*
 <FONT COLOR="#0000FF">Blue</FONT>*
 
* Yellow* White* Purple*
 *
 <FONT COLOR="#FFFF00">Yellow</FONT>*
 <FONT COLOR="#FFFFFF">White</FONT>*
 <FONT COLOR="#FF00FF">Purple</FONT>*
 

Try it

Index Global colours of the text, links, etc.

Additional attributes to the tag <BODY> allow a user to specify global colouring of the web page. Attributes of this tag include:

For example, to create a web page with a background colour of green normal text in red and links in blue is specified with the following attributes to the tag <BODY>

<BODY BGCOLOR="#00FF00" TEXT="red" LINK="#0000FF">

The document may also be given a background image. The selected image is tiled across the document and then the text of the document is written over the image(s). It is thus important to choose a background image that will not be too distracting for the reader. The background image is achieved by adding a background attribute to the BODY markup tag. For example:

<BODY BACKGROUND="backgrd.jpg">

Try it

Remember, the ability to display the colour depends on the colour depth of the monitor used by the viewer. Many people will only be able to display 256 distinct colours, and some will only have a black and white display.

For viewers with a monitor with a limited colour depth other colours will be displayed by dithering. A process which simulates the un-displayable colour, by creating a pattern of dots in colours which when viewed at a distance will fool the eye into seeing them as a single new colour. Unfortunately this reduces the resolution of the displayed area.

 

Index Logical formatting tags

The following are some of the logical formatting tags in HTML. These should be used to describe a logical unit of your document. The formatting of this logical unit may in some cases be the same as produced by other formatting tags. Remember, the tags specify logical units of the document, software other than the web browser may need this information.

Formatted text HTML markup required
The following is a citation.

 The following is 
<CITE>a citation.</CITE>
Represents computer code

 <CODE>
 Represents computer code
 </CODE>
 
A sequence of literal characters

 A sequence of
 <SAMP>literal characters</SAMP>
 
Note:
This is a blockquote of some text

 Note:<BLOCKQUOTE>This is a
 blockquote of some text
 </BLOCKQUOTE>
 
The following is a definition

 The following is 
<DFN>a definition</DFN>
The following text is emphasized.

 The following <EM>text</EM>
is emphasized.
keyboard characters.

 <KBD>keyboard characters</KBD>
 
The following text is strongly emphasized

 The following <STRONG>text</STRONG>
is strongly emphasized
The following name is a program variable

 The following <VAR>name</VAR>
is a program variable

Try it

 

Index Paragraph and line break

A new paragraph is started with the <P> tag, and may be optionally terminated with the inverse paragraph tag </P>. However, it is usual not to specify the inverse paragraph tag </P>

A line break is created by the <BR> tag, which has no inverse tag.

Formatted text HTML markup required
Last sentence of a paragraph

The first line of a new paragraph.


 Last sentence of a paragraph
 <P>
 The first line of a new paragraph.
 
A line of text.
On a new line.

 A line of text.
 <BR>
 On a new line.
 

Try it

 

Index Headings and rulers

A heading in the text is created with the <H1> tag. There are in fact six heading tags <H1> the largest to <H6> the smallest.

Formatted text HTML markup required

An H1 heading


 <H1>An H1 heading</H1>
 

An H3 heading


 <H3>An H3 heading</H3>
 
An H6 heading

 <H6>An H6 heading</H6>
 

A heading tag generates line break(s) before and after the heading text. For example:

Formatted text HTML markup required
Just before the heading.

An H4 heading

Just after the heading.
 Just before the heading.
 <H4>An H4 heading</H4>
 Just after the heading.
 

Try it

 
A horizontal ruler across the page can be created with the <HR> tag. For example:

Formatted text HTML markup required
End of a section
New section

 End of a section<HR>New section
 
Only 40% of width
New section
 Only 40% of width<HR WIDTH=40%>New section
 
The size of the ruler
New section

 The size of the ruler<HR SIZE=10>New section
 

Note:
The size of the ruler is by default specified in pixels.

Try it

 

Index Insertion of in-line images

As well as text, images may be inserted into the document. An image may be held in several formats, though the main ones used are GIF and JPEG. Due to limited bandwidth, JPEG with its high compression of picture data and its ability to represent 24 bit colour images is the best to use. Even though the JPEG compression is lossy the degradation of picture quality is not very noticeable to the human eye.

However, if the picture is very small or a graphical image then the GIF format may be the best.

Inserted image HTML markup required
imagejpeg
 <IMG SRC="image.jpg"
      ALT="image" ALIGN=TOP>jpeg
 
A gif image with a transparent background.
 A gif image
 <IMG SRC="sdot.gif" ALIGN=TOP>
 with a transparent background
 
image Text can be made to flow around an image on the left hand side by using the attribute ALIGN=RIGHT.
 <IMG SRC="image.jpg"
      ALT="mas" ALIGN=RIGHT>
 Text can be made to flow around
 an image on the left hand side
 by using the attribute
 
image The image size can also be specified using HEIGHT and WIDTH. This will speed up the construction of the page on the web browser.
 <IMG SRC="image.jpg" ALT="image" 
      ALIGN=LEFT HEIGHT=105 WIDTH=140>
 The image size can also be specified using 
 HEIGHT and WIDTH.
 This will speed up the construction of the 
 page on the web browser.
 ALIGN=RIGHT.
 
image
This can also be used to distort the picture.
 <IMG SRC="image.jpg"
      ALT="mas" HEIGHT=20 WIDTH=250>
 <BR>
 This can also be used to distort the picture.
 

Note:
There are many graphic editing programs which allow you to specify that one of the colours of a gif image is transparent when displayed by a browser. For example, LView Pro and Paint Shop Pro, allow the creation of a transparent colour in a gif image. However, in order to do this, the version used for the saved gif image must be 89a.

An image may be used as the displayed item for a hypertext link. For example: <A HREF="..."> <IMG SRC="..."> </A>.

The attributes of the <IMG> tag include:

ALT="mas"
If the image can not be displayed, then the text associated with the ALT attribute will be displayed instead of the image. This occurs, if for example the display of images has been turned off in the browser, or for some reason the browser can not display the image.
ALIGN=TOP
Causes any following text to be displayed aligned with the top of the picture.
ALIGN=BOTTOM.
Causes any following text to be displayed aligned with the bottom of the picture.
ALIGN=MIDDLE.
Causes any following text to be displayed aligned with the middle of the picture.
ALIGN=LEFT
Cause the image to be left aligned on the page. Text is flowed around the image on the right hand side.
ALIGN=RIGHT
Cause the image to be right aligned on the page. Text is flowed around the image on the left hand side.
HEIGHT=n
Set the height of the image to be n pixels.
WIDTH=n
Set the width of the image to be n pixels.

Try it

 

Index Insertion of a background image

The document may be given a background image. The selected image is tiled across the document and then the text of the document is written over the image(s). It is thus important to choose a background image that will not be too distracting for the reader. The background image is achieved by adding a background attribute to the BODY markup tag. For example:

<BODY BACKGROUND="backgrd.jpg">

 

Index Creating a list of items

There are several types of list, an un-ordered list can be created by the following markup:

Formatted text HTML markup required
  • Item one of list
  • Item two of list

 <UL>
 <LI>Item one of list
 <LI>Item two of list
 </UL>
 

Try it

An ordered list is similar to an un-ordered list, except that each entry is consecutively numbered.

Formatted text HTML markup required
  1. Item one of list
  2. Item two of list

 <OL>
 <LI>Item one of list
 <LI>Item two of list
 </OL>
 

Try it

A definition list allows a list with a backward hanging indent to be created.

Formatted text HTML markup required
Definition tag.
Text of the definition list. Which may stretch over several lines.
Another definition tag.
Text of the definition list.

  <DL>
   <DT>
   Definition tag.
   <DD>
   Text of the definition list.
   Which may stretch over several
   lines.
   <DT>
   Another definition tag.
   <DD>
   Text of the definition list.
  </DL>
 

Note:
It is a common practice for the definition tag with an image or even have it prefixed with an image.

Try it

 

Index Hyper text links

A hyper text link allows a browser of the document to navigate either: to a new point in the document or to navigate to a different document. A named point in a document is specified with an anchor tag which has the attribute NAME. For example:

Formatted text HTML markup required
Here <A NAME="marker"> Here </A>

Note:
There does not need to be any text to visibly name the anchor point.

To effect a transfer to a named anchor point, the HREF form of the anchor tag is used. For example:

Formatted text HTML markup required
Transfer to anchor <A HREF="#marker"> Transfer to anchor </A>

The # before the name of the hypertext link tells the browser that the link is to a named point in a document. As no document name is specified before the # the hypertext link is to a point in the current document. It is usual for the browser to visibly highlight the hypertext link.

Hypertext links may also link to other documents, in which case the HREF component names the document. If the file is held on another machine then a URL (Uniform Resource Locator) is used to describe the location of the document. For example:

Hyper text link to the file
file.html
Hyper text link to the file
file.html held on another machine using an URL
<A HREF="file.html"> Name </A> <A HREF="http://host/file.html"> Name </A>

To go to a named point in a file the format of the anchor is:

Hyper text link to the file
file.html at point mark
Hyper text link to the file
file.html at point mark held on another machine using an URL
<A HREF="file.html#mark"> Name </A> <A HREF="http://host/file.html#mark"> Name </A>

Try it

 

Index URL (Uniform Resource Locator)

The URL is used to specify the location of a file held on a remote machine. This is composed of several distinct components. For example, the URL http://host/file.html is composed of the following components.

http
The protocol that is to be used to access the file. In this case the HyperText Transfer Protocol. There are other protocols, but they are used infrequently.
host
The name of the machine, this can be either a symbol name such as puck.it.brighton.ac.uk or a numeric IP (Internet Protocol) address such as 193.200.1.1.
file.html
The path name of the file to which the hypertext link is to be made. This is relative to the base directory in which web pages are held. The location of this directory htdocs is defined by the person who has set up the web server.

Unix based web servers allow a convenient shortcut to accessing files placed in the directory public_html in the user's home directory. For example, the file home.html placed in the directory public_html in mas's home directory on the server machine puck.it.brighton.ac.uk, can be accessed with the URL http://www.cem.brighton.ac.uk/staff/mas/home.html

In creating the URL the characters space, =, +, <, >, %, ", /, and ? should not be used. If you do need to include these characters then represent them by the % symbol followed by the hexadecimal value of the character. The space character however, can also be represented by the character +. For example, http://www.cem.brighton.ac.uk/%25.html represents the URL http://www.cem.brighton.ac.uk/%.html.

Other access protocols can be specified by an URL. For example, to access files via the FTP (File Transfer Protocol) an URL of the form:

ftp://ftp.brighton.ac.uk/pub/mas/ada95

is used. This specifies that a link to the file/directory mas/ada95 on the machine ftp.brighton.ac.uk should be made. If mas/ada95 is a directory the viewer is presented with a list of files in the directory, otherwise the file will be displayed/transferred to you.

The full specification for an URL is:

Protocol Format Notes
HTTP http://host[:port]/path -
FTP ftp://[username[:password]@host/path If no username is specified the user anonymous is used.
Gopher gopher://host[:port]/[type[item]] -

Note:
In describing the format of an URL items enclosed in [ ]'s are optional.

 

Index Tables

Index Single cell

A table is created using the <TABLE> markup tag. The simplest table consists of a single data cell. The markup <TD> defines the start of a table data cell.

The status of the tag </TD> is somewhat unclear. Netscape 1.1 requires the end of table data cell tag </TD> to terminate the cell in certain circumstances. Other browsers sense the end of the cell by the </TABLE> or other formatting tag. The tag </TD> is not defined in the HTML specification. As unrecognized tags are ignored by a browser putting the tag in does no harm.

Formatted text HTML markup required
Text in a table

 <TABLE BORDER CELLPADDING=2>
 <TD>
  Text in a table
 </TD>
 </TABLE>
 

The following extra attributes can be added to a TABLE tag:

UNITS=
Either en, relative or pixels. This defines the units that will be used in defining other attributes. The default is pixels.
BORDER
Specifies that a border is to be placed around the table cells. The width of the border is optionally specified with BORDER=n.
CELLPADDING
Specifies the gap to be placed around the table contents.
CELLSPACING
-
BGCOLOR
Specifies the background colour of the cells.
WIDTH
Specifies the width of the table. For example:
WIDTH="80%" 80% of window width.
WIDTH=200. 200 pixels wide.

The following extra components can be added to a TD tag:

ALIGN=
Alignments are LEFT, RIGHT CENTER.
BGCOLOR=
Set the back ground colour for the cell. All cells to the right of this cell will also have this colour

Formatted text HTML markup required
Text in a table

 <TABLE BORDER CELLPADDING=2 BGCOLOR=aqua>
 <TD>
  Text in a table
 </TD>
 </TABLE>
 

Try it

 

Index Row(s) of cells

A row of cells can be created by repeating the <TD> tag.

Formatted text HTML markup required
Data cell 1 Data cell 2

 <TABLE BORDER CELLPADDING=2>
  <TD> Data cell 1 </TD>
  <TD> Data cell 2 </TD>
 </TABLE>
 

Try it

 
To form a table of many rows, the markup tags <TR> </TR> are inserted around each row in the table.

Formatted text HTML markup required
Data cell 1 Data cell 2
Data cell 3 Data cell 4

 <TABLE BORDER CELLPADDING=2>
  <TR>
   <TD> Data cell 1 </TD>
   <TD> Data cell 2 </TD>
  </TR>
  <TR>
   <TD> Data cell 3 </TD>
   <TD> Data cell 4 </TD>
  </TR>
 </TABLE>
 

Try it

 

Index Heading to a column

The tag <TH> may be used instead of <TD> if the cell is a header to a column of cells. For example:

Formatted text HTML markup required
Mnemonic Expansion
HTML Hyper Text
Markup Language

 <TABLE BORDER CELLPADDING=2>
  <TR>
   <TH ALIGN=LEFT> Mnemonic</TH>
   <TH ALIGN=LEFT> Expansion </TH>
  </TR>
  <TR>
   <TD> HTML</TD>
   <TD> Hyper Text<BR>Markup Language</TD>
  </TR>
 </TABLE>
 

 

Index Spanning rows and columns

The attributes ROWSPAN and COLSPAN of the HTML tags <TD> and <TH> are used to form data cells which span more than one row or column. For example:

Formatted text HTML markup required
Language Encapsulation
Ada 95 Using Packages
C++ Class

 <TABLE BORDER CELLPADDING=2>
  <TR>
   <TH ALIGN=LEFT>Language</TH>
   <TH ALIGN=LEFT COLSPAN=2>Encapsulation <BR> </TH>
  </TR>
  <TR>
   <TD> Ada 95</TD>
   <TD ROWSPAN=2>Using</TD>
   <TD> Packages</TD>
  </TR>
  <TR>
   <TD> C++</TD>
   <TD> Class</TD>
  </TR>
 </TABLE> 

Try it

Index Colouring table cells

The cells in a table may be coloured by using the BGCOLOR attribute. However once a cell is coloured all cells in the same row to the right will also be coloured.

This can be used to give an area of text a background colour

Formatted text HTML markup required
Language Encapsulation
Ada 95 Package
C++ Class

 <TABLE CELLPADDING=2>
  <TR>
   <TH ALIGN=LEFT BGCOLOR="#FFFFD0">Language</TH>
   <TH ALIGN=LEFT BGCOLOR="#FFFFD0">Encapsulation</TH>
  </TR>
  <TR>
   <TD BGCOLOR="#FFD0FF"> Ada 95</TD>
   <TD BGCOLOR="#FFD0FF"> Package</TD>
  </TR>
  <TR>
   <TD BGCOLOR="#D0FFFF"> C++</TD>
   <TD BGCOLOR="#D0FFFF"> Class</TD>
  </TR>
 </TABLE>
 

 

Index Using HTML special characters

The markup language uses the character < to start a markup tag. The consequence of this is that < can not be used to represent the less than character directly in a web page. The HTML markup languages defines an escape sequences of characters to represent such special characters.

The following are some of the character sequences used to represent characters that have a special meaning in the HTML language.

Character Represent by sequence Character Represent by sequence
< &lt; > &gt;
& &amp; " &quot;

Thus to include <BODY> as part of the text of a document the sequence &lt;BODY&gt; can be written.

Characters not in the normal ASCII character set are also represented by an escape sequence. This is so that they may be typed on computer systems which do not directly support the input of such characters. For example:

Character Represent by sequence Character Represent by sequence
à &agrave; ç &ccedil;

To prevent the web browser breaking a line at a space character a non breaking space character is used rather than the normal space character.. A non breaking space character is represented by the escape sequence &nbsp;. This can also be used to introduce more than one space character between words. For example:

HTML Formatted text
A&nbsp;&nbsp;B<BR>A B A  B
A B

In addition a character from the LATIN-1 character set is represented by &#nn;. Where nn represents the character code in decimal. For example:

Character Represent by sequence Character Represent by sequence
&#134; A &#65;

Printable Latin-1 characters

 

Index Literal copy and centering of text

Text can be copied literally by using the <PRE> tag. However, any HTML tags in the text will be processed. For example:

Formatted text HTML markup required

    *
   ***
  *****
 

 <PRE>
    *
   *<B>*</B>*
  *****
 </PRE>
 
Note:
The copied text is formatted using a non proportional font to preserve the layout.

Any text to be centered is enclosed between the tags <CENTER> and </CENTER>.

Formatted text HTML markup required
A line of normally formatted text.
Some lines of text
that are centered

 A line of normally formatted text.
 <CENTER>
 Some lines of text
 <BR>
 that are centered
 </CENTER>
 

Try it

 

Index Inserting an e-mail address

An e-mail address may be inserted into the document using a special form of the anchor markup tag. A user selecting this will be presented with a form on which to prepare their message for eventual sending in this case to the e-mail address:

M.A.Smith at brighton dot ac dot uk

Formatted text HTML markup required
Mail me

 <A HREF="Mike Smith University of Brighton">Mail me</A>
 

Of course your browser has to support this facility.

 

Index Automatic redirect

A page may contain a tag that will cause an automatic redirection to another URL after a specific time interval. For example, the tag

<META HTTP-EQUIV="Refresh" CONTENT="3;url=http://domain/directory/file.html">
will cause the current page to be automatically replaced with the contents of the URL http://domain/directory/file.html after 3 seconds.

Note:
This tag must be included immediately after the tag <HTML>

© M.A.Smith University of Brighton. Created July 1995 last modified April 2003.
Comments, suggestions, etc. M.A.Smith at brighton dot ac dot uk * [Home page]