这其实不是ie官方的文档，好像是别人经过实践搞出来的ie6的默认样式，这个对我们驯服ie6很有参考价值。你会从根本理解ie出现的那些bug的原因。不过可惜ie不像firefox哪样通过在地址栏输入命令来直接查看firefox的默认样式。
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INTERNET EXPLORER 6 DEFAULT STYLE SHEET
=======================================
****** HYPOTHETICAL *******************
This is a work in progress.
Values are purely indicative.
For any suggestion or addenda,
please
contact me.
[Back to CSS Test]
================================

/* Standard HTML elements
============================
Compare with the default style sheet
for HTML 4 (local copy).
These values may be affected by the
hasLayout property.
We will not take in account
the frame and frameset elements.
The table elements are not reviewed, due to
the lack of support for the corresponding
"display" values. */
The uncertain values are marked with "<" and ">".

/* Block-level elements */
html, body,
div, p,
blockquote,
ul, ol, dl,
dt, dd, address,
form, fieldset,
frame, frameset,
h1, h2, h3, h4,
h5, h6, hr, pre {display: block;}
head {display: none;}
html {margin: 0;}
body {margin: 8px;}
div {margin: 0;}
p {margin: 1em 0;}
blockquote {margin: 1em 40px;}
ul {margin: 1em 0 1em 40px; list-style-type: disc;}
li {display: list-item;}
ol {margin: 1em 0 1em 40px; list-style-type: decimal;}
ul ul {margin: 0 0 0 40px; list-style-type: circle;}
ul ul ul {margin: 0 0 0 40px; list-style-type: square;}
dl {margin: 1em 0;}
dd {margin-left: 40px;}
address {margin: 1em 0; font-style: italic;}
form, fieldset {margin: 0;}
fieldset {border: 1px inset <sistem color>;}
h1, h2, h3, h4, h5, h6 {font-weight: bold;}
/* the following font size and vertical values are purely indicative,
since they depend on the font size/family set on the
BODY element */
h1 {font-size: 2em; margin: .6em 0;}
h2 {font-size: 1.5em; margin: .8em 0;}
h3 {font-size: 1.1em; margin: 1em 0; }
h4 {font-size: 1em; margin: 1.3em 0;}
h5 {font-size: 0.8em; margin: 1.6em 0;}
h6 {font-size: 0.6em; margin: 2.3em 0;}
hr {border: 2px outset <sistem color>;}
pre {margin: 1em 0; font-family: monospace; white-space: pre;}


/* Inline elements */
a, i, cite, em, var, acronym,
tt, code, kdb, samp, del, ins,
u, dfn, sub, sup, big, small {display: inline; }
a:link {color: blue; text-decoration: underline; }
a:visited {color: purple; text-decoration: underline;}
i, cite, em, var {font-style: italic;}
tt, code, kbd, samp {font-family: monospace;}
del {text-decoration: line-through;}
u, ins {text-decoration: underline;}
sub {
vertical-align: sub;
font-size: smaller;
line-height: <value>;
} /* greater than "normal" */
sup {
vertical-align: super;
font-size: smaller;
line-height: <value>;
} /* less than "normal" */
big {font-size: larger;}
small {font-size: smaller;}
/* Replaced elements */
/* We will take in account only INPUT and TEXTAREA */
input, textarea {display: inline-block;}