Apple has launched a new “Made for Apple Watch” program that confirms its support for third-party bands and accessories. The Cupertino company has also released new design guidelines that will make it easier for accessory makers to build new products for the device.

Just like its Made for iPhone and Made for iPod (MFi) programs, Apple’s new Made for Apple Watch program will provide approval for third-party accessories that meet its requirements.

A new “Band Design Guidelines for Apple Watch” PDF outlines those requirements, and provides useful guidelines developers can work with — including detailed schematics of the Apple Watch that should make building straps and other accessories easier.

To earn Apple’s approval, third-party Watch bands must pass a number of stringent tests, which cover things like durability and corrosiveness. They must also be designed to detach easily when users want to remove them, and provide sufficient “adjustability” for different wrist sizes.

Apple also recommends the materials that should be used to create bands and “lugs” — the components that connect the band to the Watch — such as silicone, glass-filled nylon, and stainless steel.

Third-party accessory makers have been announcing their own straps, charging cradles, and other add-ons for months now, but it wasn’t totally clear whether Apple would actually embrace these or leave them out in the cold in favor of its own straps.

Now the Made for Apple Watch program confirms that the company is encouraging others to build for Apple Watch and create a budding ecosystem for adopters.