Don Hollander (of the Universal Acceptance Steering Group) posted this helpful article on LinkedIn, excerpted here with underlined emphasis added:
… The expansion allows people to claim a domain name that best reflects their sense of identity. While this expansion is critical in bringing the next billion people online and growing the global Internet economy, the incorporation of these new domains across the global Internet is not an entirely automatic process. CIOs, web administrators, application developers and others have an important role to play in making sure their applications are compatible with the evolved Internet infrastructure.
… Many organizations and business have not updated their systems to accommodate the new domains or, in other words, become Universal Acceptance (UA)-ready. As a result, many applications and Internet-connected devices and systems are unable to accept, validate, store, process or display all domain names. This causes problems for organizations and headaches for users because if the applications do not recognize or appropriately process the new domain names or email addresses that use these extensions, it will result in lost customers and a poor user experience.
… To address these issues and provide support, stakeholders and industry leaders such as Apple, GoDaddy, Google, ICANN, Microsoft and Verisign, created the Universal Acceptance Steering Group (UASG). The UASG exists to help organizations ensure their systems are UA-ready and able to accept all domain names and email addresses in any valid script.
… The UASG has developed helpful guides and resources which are available at https://uasg.tech/documents. Of particular note is the Quick Guide to Universal Acceptance (UASG005) as well as the Introduction to Universal Acceptance (UASG 007), a comprehensive technical document on Universal Acceptance and the key issues that developers and system architects need to know.