Netscape's HTML Extensions Summary

This list summarizes the extensions Netscape has made to HTML.

The elements shown here are in all capital letters; the attributes are indicated by initial capital letters. In order to benefit from the information in this file, view both its HTML source as well as its rendered form in a Web browser. Some of tags that are explained in the list below are also demonstrated in this file.

HTML structure and comment elements

Netscape adds backgrounds to the BODY element. by adding the follow attributes to the BODY element:

Background: this attribute's value is the URI of the graphic that will be tiled as the background of the page. The user will not see this background for non-compliant browsers, if image loading is turned off, or if the user has overridden the background images in their preferences.
Bgcolor: this attribute allows the user to specify a solid background color. The color is specified using a hexadecimal color code:
#RRGGBB
where RR, GG, BB are the hexidecimal digits specifying the Red, Green, and Blue values of the color. For example:
black = #000000 yeilds BLACK
blue = #0000FF yeilds BLUE
red = #FF0000 yeilds RED
orange red = #FF4500 yeilds ORANGE RED
white = #FFFFFF yeilds WHITE
(NOTE BENE: When printing, white letters are printed WHITE (Invisible!) by your Printer)
If a background file specified in the Background attribute cannot be found, the color specified by the Bgcolor tag will be used. This Bgcolor will also be used if the user has auto load images off. This Bgcolor will also be used as a table border color on Netscape for Windows.
Text: this attribute specifies the color of the document's text.
Link: this attribute specifies the color of the document's hotspots.
VLink: this attribute specifies the color of visited links.
ALink: this attribute specifies the color of the active link (the color it appears while the user is selecting it).

The HEAD and Related Elements

Netscape adds:

ISINDEX attribute Prompt to specify the message a user sees for a searchable index. Example: Prompt="Enter keyword(s)."

The BODY and Related Elements

HR: attributes added:
- Size="number": how thin the line should be in pixels. Example 1, below is 15 pixels thick and runs the whole width of the display.
- Noshade: turns off shading to create a solid bar. Example 2, below is a 1 pixel solid bar which runs the whole width of the display.
- Width="number|percent": the width of the line, either expressed as width in pixels (number, as in Example 3 below which is 100 pixels wide) or a relative with as a percent of the current display width (not page width). Example 4 is 33% of the display width. These lines are by default centered (default can be overridden with the Align attribute).
- Align="left|right|center": the alignment of horizontal lines that are less than the full width of the page. Example 5 is a 5 pixel bar which is 10% of the display wide and aligned to the right.

HR Example 1. <HR Size="15" />:

HR Example 2. <HR Noshade />:

HR Example 3. <HR Noshade Width="100" Size="5" />:

HR Example 4. <HR Noshade Width="33%" Size="5" />:

HR Example 5. <HR Width="10%" Align="right" Size="5" Noshade />:

UL: attribute added: Type="disc|circle|square"
UL Type="disc":
- item
- item
UL Type="circle":
- item
- item
UL Type="square":
- item
- item
OL: attribute added: Type="A|a|I|i|1": A = capital letters; a = small letters; I = capital roman numerals; 1 = numbers (default)
1. Type="I"
  1. Type="A"
    1. Type="1"
      1. Type="a"
        
        Type="i"
        Next "i" item
      2. Next "a" item
    2. Next "1" item
  2. Next "A" item
2. Next "I" item
Unordered List LI attribute added: Type="disc|circle|square"
- Type="disc"
- Type="circle"
- Type="square"
Ordered list LI attribute added: Type="A|a|I|i|1": A = capital letters; a = small letters; I = capital roman numerals; 1 = numbers (default)
1. Type="A"
2. Type="a"
3. Type="I"
4. Type="i"
5. Type="1"
Order List LI attribute added: Value="number"
1. Value: changes the displayed value for the list item
IMG: attributes added:
- Align="left|right|top|texttop|middle|absmiddle|baseline|bottom|absbottom" Examples:
  left aligned image
  
  right aligned image
  
  top text aligned image
  
  middle text aligned image
  
  bottom text aligned image
- Width="value" Height="value"; width and height of the image in pixels; speeds up processing if given because Netscape can layout the page before images download. If inaccurate, Netscape will size the image to the given width and height.
- Border="value"; thickness of the border around images
- Vspace="value"; Hspace="value"; controls the blank space above and below (Vspace) and to the left and right (Hspace) of an image
BR: attribute added:
- Clear="left|right|all": used in conjunction with image placement (see examples above) to flush text to clear the left or right (or both) margins
NOBR: (NO BReak). All text placed between the start and end of the NOBR element will not have line breaks inserted.
WBR: (Word BReak) Within a NOBR element, you can define where a line break should be made. Outside of the NOBR element, WBR is a hint, (use BR to force a linebreak).
FONT Size: You can cha nge t he font size in sizes from 1-7 or use + or - to ch ange relative to the current base size (default 3).
BASEFONT SIZE: changes the current base font size (default of 3 to another size in the range 1-7.
<BASEFONT SIZE="1"> </BASEFONT>
<BASEFONT SIZE="2"> </BASEFONT>
<BASEFONT SIZE="3"> </BASEFONT>
<BASEFONT SIZE="4"> </BASEFONT>
<BASEFONT SIZE="5"> </BASEFONT>
<BASEFONT SIZE="6"> </BASEFONT>
<BASEFONT SIZE="7"> </BASEFONT>
Font accumulations of attributes:
Italic font can accumulate typewriter and bold
Compare that to: italic, typewriter, and bold.
CENTER: centers text
BLINK: creates blinking text
TABLE: extensions over Level 3's table attributes.

References

Netscape Navigator Extensions to HTML
at http://www.netscape.com/home/services_docs/html-extensions.html
Mozilla DTD
at http://www.halsoft.com/sgml/Mozilla/DTD-HOME.html
Controlling Document Backgrounds, from Netscape
at http://www.netscape.com/assist/net_sites/bg/index.html

NO LONGER VALID, WAS:
http://www.rpi.edu/~decemj/index.html = John December / 04 Jun 95

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