Xcode 16 introduces an "Asset Symbols" property in asset catalogs to control symbol generation.This property allows Swift Packages to opt-out of symbol generation, which was previously not possible.The default setting is "Inherited," which inherits from project/target settings."Extensions On" enables symbol generation, while "Extensions Off" disables it for individual asset catalogs in Swift packages.Symbol generation creates Swift and Objective-C symbols for colors and images in the asset catalog.By default, symbol generation is enabled for new projects, but it can be customized in project settings.Generated color symbols are static properties of ColorResource, while image symbols are static properties of ImageResource.Framework extensions for SwiftUI, UIKit, and AppKit types are also generated, but framework support can be restricted.The initial letter of generated symbols is lowercase, even if the asset catalog name starts with an uppercase letter.This opt-out feature allows Swift Packages to avoid symbol generation conflicts and provides more control over asset symbol usage.