• Joomla! CMS 2.5.x

• INT Forces the value to be an Integer
  
  
• UINT Forces the value to be an absolute number (-4.2 becomes 4.2)
  
  
• FLOAT Forces the value to be a floating point value
  
  
• BOOL Forces the value to be true or false
  
  
• WORD Strips anything that is not letters (including numbers)
  
  
• ALNUM Forces the value to be alphanumeric (Letters and numbers only. No special characters)
  
  
• CMD Forces the value to be alphanumeric plus the following three special characters _ (underscore) . (dot) - (dash)
  
  
• BASE64 Forces the value to be a base64 encoded the string. Note it does not encode the string, it simply strips characters that may not exist in a base 64 encoded string.
  
  
• STRING Removes HTML
  
  
• HTML Allows basic HTML
  
  
• ARRAY Forces value to be an array
  
  
• PATH Forces value to be a file path
  
  
• USERNAME Forces value to only contain characters allowed in the selection of a Joomla username
  
  
• UNSET Completely remove any input
  
  
• RAW Allow any content
  
  
• URL Forces content to be a URL
  
  
• TEL Forces content to be a properly formatted US phone number

1. Open the database to the Joomla 1.5.x website
2. Browse the table "jos_components" (or "#__components" where "#_" is the site table prefix. default is "jos").
3. Open the row where name="User Manager"
4. Set the value under params for AllowUserRegistration
   • allowUserRegistration=0 to disable it.
   • allowUserRegistration=1 to enable it.

• Applies to Joomla 1.6.x, 1.7.x, 2.5.x

1. Backup the file \templates\system\error.php
2. Create a replacement file called error.php including the below code
3. Change the message "The Page you are looking for..." to what you want.
4. Change the link "www.joellipman.com" to the "www.yoursitename.com".
5. [Optional] If you want the image that creates the shadow you can download it here. I put it in the folder \templates\system\images.

What?
If you get something like the following error:

Warning: call_user_func() [function.call-user-func]: First argument is expected to be a valid callback in /home/.../templates/rt_affinity/rt_sectionrows.php on line 311

How?

1. Copy & backup the file /public_html/.../templates/rt_affinity/rt_sectionrows.php
2. Find the following piece of code around line 311:
   copyrawstyler

   foreach($this->horizontalCookie[$row] as $block) {
   	$block = str_replace('-', '', $block);
   	$this->module_row1 .= call_user_func($block, $this, $mClasses);
   }

   1.  foreach($this->horizontalCookie[$row] as $block) { 
   2.      $block = str_replace('-', '', $block); 
   3.      $this->module_row1 .= call_user_func($block, $this, $mClasses); 
   4.  } 
3. And change it to:
   copyrawstyler

   foreach($this->horizontalCookie[$row] as $block) {
   	if(!empty($block)) {
   		$block = str_replace('-', '', $block);
   		$this->module_row1 .= call_user_func($block, $this, $mClasses);
   	}
   }

   1.  foreach($this->horizontalCookie[$row] as $block) { 
   2.      if(!empty($block)) { 
   3.          $block = str_replace('-', '', $block); 
   4.          $this->module_row1 .= call_user_func($block, $this, $mClasses); 
   5.      } 
   6.  } 

• Joomla 2.5.8
• Yootheme Template 2012