<basefont size=size>

Changes the size of the basefont for the rest of the document. This affects text effects

<basefont size=2>
Basefont is size 2, <b>bold</b> <i>italic</i> <tt>tt</tt><br>
<basefont size=3>
Basefont is size 3, <b>bold</b> <i>italic</i> <tt>tt</tt>

Basefont is size 2, bold italic tt
Basefont is size 3, bold italic tt

<BIG> ... </BIG>

Uses a <big>Bigger</big> font style if possible.

<BR [clear="left"|"all"|"right]>

<BR>
Inserts a line break
and continues on the next line.

<BR clear="left">
this is some text, this is some text. After a line break
Text continues on the next line which has a clear left margin.

<BR clear="right">
This is is some text, this is some text, After a line break
Text continues on the next available line with clear space along the right hand margin of the page.

<center>..</center>

<center>
Everything contained in the center tag is ..

centered
</center>
You could use the proposed <align="center"> but it doesn't center everything

<HR [size=size] [width=width] [align=left|right|center] [noshade] >

<ISINDEX [prompt=text]>

Default
using the prompt attribute
<ISINDEX prompt="What?">

<li [type=...] [value=number]>

The parameters added to the <LI> tag are meant to allow more flexibility. Now it is possible to completely lose track of numbering and style within a list:
  1. list item 1
  2. list item 2

Use the extensions to <OL> and <UL> in preference to the extensions to <LI>.

<ol [type="1"|"a"|"A"|"i"|"I"] [start=number]>

<NOBR>...</NOBR>

<NOBR>
Text within NOBR can not be broken and ends up on a very very very loooooooooong line.
</NOBR>

<ul [type="disc"|"circle"|"square"]>

<ul type=disc> </ul>

<WBR>

A WBR tells netscape where a word can be broken if it needs to be. An example of its use is where a narrow band of text occurs between two pictures.

The text might contain long strings like this-is-a-long-string-with-lots-of-hyphens-in-it which just cant be broken very easily without screwing up the page appearance

by adding WBRs the problem is solved. this-is-a-long-string-with-lots-of-hyphens-in-it.

character codes

In addition to the usual & escaped entities:
&reg; -> Registered Trademark -> ®
&copy; -> Copyright -> ©

backgrounds

<BODY [BACKGROUND=image] [BGCOLOR=#rrggbb] [TEXT=#rrggbb] [LINK=#rrggbb] [VLINK=#rrggbb] [ALINK=#rrggbb] >
Document here
</BODY>

BACKGROUND
tiles the specified image onto the background
BGCOLOR
The colour to use for the background (if not an image)
TEXT
the colour of the normal text (normally #000000)
LINK
links prior to activation
ALINK
activated links
VLINK
visited links

Examples

dynamic documents and the art of pushing and pulling

I'm afraid the explanation is too esoteric for me to simplify (or understand) So you're going to have to look at the original netscape documentation for this

With the release of Java, The push pull mechanism of netscape will have to be dismissed into the domains of the obsolete.

<sub> ... </sub>

Subscripts, Ideal for really <sub>tiny</sub> text.

<sup> ... </sup>

Superscripts, Ideal for really <sup>tiny</sup> text. in a different position to subscripts 1

<small> ... </small>

Uses a <small>smaller</small> font if available.

tables

Examples
<TABLE [border=size] [cellpadding=value] [cellspacing=value] [colour information]>...</TABLE>
This contains the other table tags.

<TR [rowspan] [align=alignment] [valign=alignment]>..</TR>
The current row in the <Table>
<TD [nowrap] [align=alignment] [valign=alignment]>..</TD>
A data cell in the current <TR>.
<TH [nowrap] [align=alignment] [valign=alignment]>..</TH>
This is a Header cell and is similar to the <TD> tag except that the default font is centred and bold.
<CAPTION [align=alignment]>..</CAPTION>
Captions can appear anywhere in a <Table> but can not be contained within <TR>, <TD> or <TH> tags.

Captions align to the top by default.

<MAP NAME="map_name">...</MAP>

This defines a client side image map.

<P align=[left,right,center]>...</P>
<DIV align=[left,right,center]>...</DIV>


<P align=left>
the default behaviour of your browser is for the text to line up with the left hand edge of the page.
</P>


<P align=right>
But it can
be
aligned to the
right hand side.
</P>


<P align=center>
Or to the center
just like the <center> tag

</P>

uploading data using <INPUT type="file">

Filling forms can be tedious, sometimes more detailed information is needed. This is possible using: 

<FORM ENCTYPE="multipart/form-data" ACTION=URL METHOD=POST> 

  <input name=variable_name type="file">

</FORM>
The file will be sent to the server and it is the responsibility of the script that gets it to decipher the contents of file contained in variable_name

This mechanism could also be used to mail a file.

<Marquee>text to scroll</Marquee>

If you're lucky enough to be using internet explorer you'll see a cool but seriously irritating scrolling message. "Where do you want to go today?" is something you're unlikely to be asked by the average taxi driver.