The name of the custom attribute key.
- iOS 9.0+
- macOS 10.13+
- UIKit for Mac 13.0+Beta
- Core Spotlight
The key name is a string that contains only ASCII characters and no punctuation other than the underscore (that is “_”). The prefix
k is reserved. To create a custom attribute key name, it’s recommended that you use a reverse DNS format that includes your company name and does not include the period character (“.”). For example, a key name of the form
com works well.