Major advantages and disadvantages in using <?php , <? ,<script language=“php”> , <% in php

hi i saw there are four types of tags using in php .

<?php

?>

and

<?

?>

and

<script language=“php”>

</script>

and

<%

%>

and only the first o开发者_运维知识库ne is using and others are deprecated .

i want to know the major advantages and disadvantages of each . and want to know why the 2 ,3 ,4 ones are deprecated .

1. Normal php tags
2. XML tags
3. HTML tags
4. ASP tags

I think the disadvantage of deprecated tags is that they are common in other languages too, not only php.

They are going to be deprecated in php6

Because these php short tags are not supported on all servers