1. There should not any PHP closing tag (?>)in controller & Model file.
2. Indentation should consist of 4 spaces. Tabs are not allowed.
3. The target line length is 80 characters, The maximum length of any line of PHP code is 120 characters.
4. Line termination follows the Unix text file convention. Lines must end with a single linefeed (LF) character. Linefeed characters are represented as ordinal 10, or hexadecimal 0x0A