HTML5 Guidelines

• Optimize loops and timers
• Minimize DOM access
• Use Feature detection versus Browser detection for efficiency
• Do not use ‘eval ()' functions due to security risks
• Avoid global variables as they may result in naming conflicts and cause code to break
• Account for syntax differences and requirements between browsers (particularly IE)
• Request animation frame (use whenever possible as an alternative to set interval)

• creative should contain code that checks browser support for request animation frame feature
• setInterval (use as a fallback for older browsers (IE9 and earlier))
• setInterval is code and computer resource intensive and should be avoided
• Do not use styles/CSS to change any properties of the native html elements including but not limited to: < html >, < body >, < p >, etc.

• Please test your ad on the following browsers to ensure that it works as expected across each:

1. Firefox Mac/PC, most recent version
2. Chrome Mac/PC, most recent version
3. Internet Explorer, 10+
4. Safari, most recent version

• Ad code should be error-free when testing
• There should be no errors in the browser’s web development console or web inspector
• Ad code should be ready to serve live
• Remove any code that sets clickTAG to another url

Any code for demonstration purposes should be removed, for example:

1. CSS modifying standard page tags like < body > , < p > , etc
2. Code that centers ad
3. Code that colors the page

• Ad unit(s) should be set to top/left with a zero pixel margin
• Any console.log calls should be removed or commented out
• Ad code should be JS Lint compliant
• Always use JS to set element style to avoid the initial null or zero style value detection or check
• Initial and sub loads should be within Yahoo specs