How do I can change the default description of elements? I'm trying to change the default descriptions in different pages like (add users). I tried devel themer to find out where there descriptions are came from but it showed nothing. for example look at this picture (add user) :



how do I can change the texts displayed by red line?



Update

I tested this code in template.php

function MYTHEME_form_alter(&amp;$form, &amp;$form_state, $form_id){
if($form_id == "user_register_form"){
    $form['account']['name'] = array(
            '#title' =&gt; t('New username'),
            '#description' =&gt; t('New description'),
    );
    }
}
you can find the descriptions at user.module under user directory (in modules directory)

you can find those descriptions under user_account_form function 

Ex, E-mail address field description below.

$form['account']['mail'] = array(
    '#type' =&gt; 'textfield',
    '#title' =&gt; t('E-mail address'),
    '#maxlength' =&gt; EMAIL_MAX_LENGTH,
    '#description' =&gt; t('A valid e-mail address. All e-mails from the system will be sent to this address. The e-mail address is not made public and will only be used if you wish to receive a new password or wish to receive certain news or notifications by e-mail.'),
    '#required' =&gt; TRUE,
    '#default_value' =&gt; (!$register ? $account-&gt;mail : ''),
  );


But it's better to  Use hook_form_alter to achieve it