I haven’t seen any replies yet but as I think it is an important topic I would like to chime in. In theory all of the cases mentioned below should be tested but as you indicated this is cost prohibitive. Would it be an idea to split this list into tiers ? Ie a minimal set of tests to make it workable but not ideal and more advanced tests that have the full solution. In the minimal set there would be no IDN, but full support for punycode (a-labels) The advanced set would allow for IDN everywhere and left-right/right-left cases. Ron Geens DNS Belgium On 17 Dec 2015, at 01:15, Don Hollander <don.hollander@icann.org<mailto:don.hollander@icann.org>> wrote: During recent calls, there’s been a desire for some UA Use Cases. This from a document we had developed some time ago. I would welcome people’s suggestions for which of these should be tested - as there’s a cost associated with testing each one. Don Universal Acceptance Use Cases for UA Readiness Evaluation Purpose: To provide Use Cases for developers to use when evaluating the UA Readiness of their systems. This list will provide generic examples as well as specific names that can be used for testing. Background: Background on Universal Acceptance to go here Domain Names: Examples • secondlevel.toplevel • 域名.toplevel • secondlevel.域名 • 域名.域名 • secondlevel.punycode • punycode.toplevel • punycode.punycode • Second. חלק עליון(Right-to-left TLD) • שני. חלק עליון (Right-to-left second level and top-level) Path Cases (IRIs) • secondlevel.toplevel/unicode • 域名.toplevel/unicode • secondlevel.域名/unicode • 域名.域名/Unicode • secondlevel.punycode/unicode • punycode.toplevel/unicode • punycode.punycode/unicode • Second. חלק עליון/Unicode (Right-to-left TLD) • שני. חלק עליון /Unicode (Right-to-left second level and top-level) E-mail Addresses: • localpart@domain.tld<mailto:localpart@domain.tld> • localpart@域名.tld • localpart @domain.域名 • localpart@域名.域名<mailto:localpart@xn--eqrt2g.xn--eqrt2g> • localpart@domain.punycode<mailto:localpart@domain.punycode> • localpart@punycode.tld<mailto:localpart@punycode.tld> • localpart@punycode.punycode<mailto:localpart@punycode.punycode> • 域名@域名.域名 • שני. חלק עליון@localpart