You can pass strings, Booleans, integers, floating point values, and None as user attribute values. If you want to target audiences based on the version of your application that they are using, you can also pass in a string formatted as a [semantic version](🔗), then define a `
version` audience condition in the Optimizely app. The examples below show how to pass in attributes.
During audience evaluation, note that if you do not pass a valid attribute value for a given audience condition—for example, if you pass a string when the audience condition requires a Boolean, or if you simply forget to pass a value—then that condition will be skipped. The [SDK logs](🔗) will include warnings when this occurs.