Question

I found this form where the input value are populated with variable inside this

<%=

tag,

what is this tag?

To which programming language does it belong ?

<input type="hidden" name=" requestparameter " value="<%= requestparameter %>">

Answer 1

It is an asp tag that can be enabled in php by setting asp_tags=1 in php.ini file. When enabled,

<%
  //php code here
 %> 

is equivalent to

<?php 
  //php code here
?>

In this case

<input type="hidden" name=" requestparameter " value="<%= requestparameter %>">

is equivalent to

<input type="hidden" name=" requestparameter " value="<?php echo(requestparameter) ?>">