Validation of Web Standard (W3C Validation)
The main reason of this phase is that many browser vendors have made their programs so differently. Keeping web standard may help your service shown identically regardless of browser environment. W3C, who enacts the web standard offers a service to validate online. (http://validator.w3.org) Insert your site address and click Check button to conduct validation. If you meet some errors or warnings, you’d better remove them all.

Optimization
Optimization is important to improve the performance of the service. According to the statistics from Amazon.com, 0.1 second speed-up brings 1% revenue increment. There are some issues about the method so you can consider them. Here is a list of optimizing stuffs.

- Locating inline script and stylesheet(CSS) properly.
- Deferred script.
- Gzip compression.
- Seeing how CSS selector operates in browser.
- Optimization of images (GIF, JPEG, PNG, etc)

Security Manners
It is essential to sanitize user’s input. You’ll get a big trouble by hackers who targets at the core information in your site unless missing security managing process. That is, the personal data and information could be divulged or manipulated. The range of security is broad but you can see the following issues primarily.

- XSS (Cross-site script) attack.
- SQL injection.
- Intercepting user session.
- Exploiting vulnerabilities of browser.