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 .

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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.

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They are going to be deprecated in php6

Because these php short tags are not supported on all servers