This project is an attempt to create a well maintained, informative and categorized cheat sheet to highlight HTML5 as well as other client side and related security issues and ways to avoid them. The project is meant to target web developers as well as security researchers and especially browser vendors since many of the problems we found are based on faulty or quirky implementations. Focus is on completeness, comprehensibility and timeliness as well as continuity - benefits many other related cheat sheets don't exactly provide.