Microsoft appears to be taking an even tougher stance on bulk publishing and "spam" apps in the Windows Phone Marketplace this week. In a blog post addressed to Windows Phone developers, Todd Brix, Senior Director of the Marketplace, has outlined some new efforts to ensure developers follow Microsoft's guidelines.

There are four key areas that Microsoft is attempting to improve. The first is trademark issues, Microsoft wants to make it clear that app publishers should avoid using trademarked terms like "MSN" or "YouTube" in their app names unless they are simply using it to describe the features of the app. "Reader for MSN" would be acceptable to describe an app, and if a developer owns a trademark or has secured permission to use one then they will avoid having their application pulled from the Marketplace.

Microsoft is also aiming to weed out bulk publishers, who violate policies and submit the same app to multiple Marketplace categories, and focus on quality applications. The software maker wants developers to differentiate apps that are similar by ensuring the branding isn't too dominant and that the icons are different. Keywords, used by developers to describe their apps, will also be restricted to just five starting this week. Microsoft found that developers were exceeding the five keyword policy, with some using poplar search terms such as "Justin Bieber" and "YouTube" to tag their apps. "If we find a keyword that’s not relevant to your app’s function or content, we’ll delete that keyword, says Brix.

Finally, Microsoft is also attempting to be transparent about its policies towards apps that are sexual in nature. Although the company doesn't allow "sexually suggestive or provocative" images or content in apps, it does permit swimsuit apps and "content you occasionally see on prime-time TV." Microsoft says it will be "paying more attention" to icons, titles, and content of these types of apps in future to ensure they're "more subtle and modest."