Your question is very vague, The PHP Codes as you call them could be referring to the server-side code written in PHP that a website uses. for more information about PHP go to php.net
if i got your question right, you mean "what are php tags?" your should write PHP codes between <?php ... ?> where ... should be replaced by codes that you need. But if you mean "what are php codes?": there are some default codes that you may find them on php.net, and the other part is codes (Functions or classes) that other programmers develops..
Ratinonal program in php
You can use the GD extension for PHP to edit image files.
PHP 6 hasn't been released yet.
using servlets, php, and database we can connect import codes into java
PHP documents are files that contain PHP codes, JavaScript, HTML, etc. which are executed via the server. PHP files that are stored in the computer can be found by typing ".php" in the search (this is the extension of PHP files).
Server-base language mean code you write will be processed on server instead of client, ex: when you request a page from server (a php page) it will be first processed on server then server will send you result of codes.. it means you won't see php codes on the page only result of it.
One can find information and tutorials on Cart PHP by viewing videos on video sharing webpages, such as Youtube. Alternatively, one can try sites such as Quality Codes for a tutorial.
Follow this link. It explains how to pull the codes without a code reader. http://nissanhelp.com/diy/common/nissan_engine_codes_read_2.php
I think this is what you are looking for. go here and see. http://www.poqbum.com/tutorials/customize_text_4.php
go to http://arcentral.net/Codes/NTSC/Naruto_Clash_of_Ninja_2.php and there you go.
Answer: Php 2510% of Php 250= 10% * Php 250= 0.10 * Php 250= Php 25