Let's talk web coding. Oh everyone thinks they know HTML and CSS real well but do you really know it?

Let's break it down:

So called HTML experts do you know:

1.) Fieldset and legend tags
a Fieldset tag surrounds the element with a border. a Legend tag adds a caption to it.

2.) What valign does
Sets the vertical alignment of a table row. Can be equals to: TOP, Middle, BOTTOM, BASELINE.
Replaced by stylesheet element: vertical-align.

3.) What clear is used for, example <br clear="all" />
Used to force the line after it to appear on a new line, and not beside the previous element.

4.) What you are the size is really doing in a font tag
Umm.. What?

5.) What titles are
Used for short informative text, when hovering over images, links and other elements.

6.) What alts are really used for
Is used when the image does not load, to describe what the picture is about.

7.) What divs are used for
Defines a division or section in a page.

8.) What spans are used for
Defines a group of elements that need to be in another section.

9.) How to use frames
Um..[code]<frameset cols = "15%, 15%,*">
  <frame src ="potato.php" />
  <frame src ="pie.php" />
  <frame src ="food.php" /> 
</frameset>[/code]

10.) Tags such as marque, the apprioate time to use them
[b]marquee[/b] is used to display horizontally scrolling text. The only time to use them is when you want to annoy someone.

11.) XHTML Standards
XHTML Standards were created to seperate content from design, and to allow mobile devices to access sites easier.
in XHTML, tags have to be closed, and single tags need to be self closed. example: [code]<br />[/code]

So called CSS experts do you know how to:

1.) Make a background repeat
2 ways:
[code]#element{ 
background-image: url('images/background.png');
background-repeat: repeat;
} [/code]or[code]#element{ 
background: url('images/background.png') repeat;
}[/code]

2.) Position a background
Also 2 ways:
[code]#element{ 
background-image: url('images/background.png');
background-repeat: repeat;
background-position: top-right;
} [/code]or[code]#element{ 
background: url('images/background.png') repeat top right;
}[/code]

3.) Give a background(image to anything) to anything
This will give h2 an image background.
[code]h2{
background: url('images/background.png') repeat-x;
}[/code]

4.) Add dashed, groved, ridged, etc. borders to elements
[code].element {
border: 1px n #CCC;
}[/code]
n being: hidden/dotted/dashed/solid/double/groove/ridge/inset/outset

5.) The apprioate use of classes
The [b]appropiate[/b] use of classes is when an element is repeated, for single elements, using an id is recommended.

6.) Avoid using tables in web layout
[url=http://www.shadyphp.com/portfolio/das/]Oh look, a table free layout[/url]
[url=http://blog.shadyphp.com/]Another table free layout![/url]
Those who know me will know that I can do table free layouts easily.

7.) Make a div float
[code]<div style="float: left; width: 200px;">This will float left</div>
<div style="margin-left: 210px;">And this will appear to the right of it.</div>[/code]

8.) Use absolute and relative positioning
[code]<style>
#abs{
position:absolute;
color:red;
left:100px;
top:150px;
}
#rel{
position:relative;
color:orange;
left:100px;
top:150px;
}
</style>

<h1 id="abs">Absolute!</h1>

<h1 id="rel">Relative!</h1>[/code]

9.) Use z-index
[code]#elemnt{ 
z-index: -1
}  [/code]

There is more but I hate when people who know none of that call themself an expert.