Google is cleaning up the official Google Play store a bit, making several changes to its Developer Program policy to improve its user experience and address issues like “deceptive app names and spammy notifications.” In an email sent out today to Google Play developers, the company outlined several new changes to its policies.

From now on, Google will restrict the use of app names and icons that it deems too similar to existing system apps. These apps typically attempt to confuse or misdirect users by purporting to be an official, pre-installed application, rather than something the user downloaded themselves.

Google is also making its policies about collecting user data clearer. The new policies explicitly prohibit the collection of user data without permission, and require developers to specifically outline what user data they are collecting. Apps are now expressly prohibited from sending SMS or email messages on behalf of a user without permission.

One of the most significant changes, however, is a new section dedicated to the Google Play ad policy. It’s now clear that Google considers the ads in an app part of that app, meaning all of Google’s policies around content and data collection apply just as much to the ads an app show to the app itself. In addition, Google Play developers must now make it clear what app an ad or a notification originates from. Users must also be allowed to dismiss an ad without penalty, and ad walls — advertisements a user must interact with in order to gain access to an app — are now expressly prohibited.

In the past Google has been criticized for what some see as relatively lax quality controls in Google Play. Google does not pre-screen or censor apps before they appear in the Google Play store, a policy that some unscrupulous developers have taken advantage of.

Earlier this month mobile security company Lookout reported almost five percent of all apps use “aggressive ad networks” — ad providers that access personal information such as email without notifying the user, change a user’s bookmarks or settings without asking permission or even serve ads outside the app they are connected to. Today’s changes to Google’s Developer Program seem to be aimed squarely at those kinds of apps.

“The way I think about it is the apps and Google Play itself are evolving,” says Chris Yerga, engineering director for Google Play. “What we’re trying to do here is give developers very concrete guidance about what’s expected of them.”

In addition to the changes noted above, apps with the primary function of driving affiliate traffic to a website, or load websites that don’t belong to the application developer (unless they have permission from the website’s owner/administrator) are now prohibited. Apps that encourage users to download applications from outside the Google Play store are also banned under the new guidelines.

All these changes are in addition to the changes to Google’s payment policy, which we cover in more detail here. The new developer guidelines can be found here.