Re-posting my comments and questions on this PRI to the list. I've already submitted them as formal feedback.
. I support this proposal. I have the following questions: 1. The existing RIS-based flag mechanism is based on ISO 3166-1 (TUS 7.0 §22.10). In this proposal, "valid" tag sequences would instead be determined by CLDR data and LDML specification. Is there any precedent for CLDR to define the validity of Unicode character sequences? 2. What is the policy on generating flag tags with deprecated unicode_region_subtag or unicode_subdivision_subtag values, such as "[flag]UK"? How "discouraged" would such a tag be? Should tools allow users to create such a tag? 3. The subdivisions.xml file contains a "subtype" hierarchy, reflecting the "parent subdivision" relationship in ISO 3166-2. So region 'FR' contains subdivision 'J' (Île-de-France), which itself contains subdivision '75' (Paris). Is there any significance to the "subtype" hierarchy as far as flag tags are concerned, or are "[flag]FRJ" and "[flag]FR75" equally valid? 4. The entry for "001" in subdivisions.xml contains each of the two-letter codes for regions (countries) that have their own subdivisions. This is less than the set of all regions; for example, Anguilla (AI) does not have ISO 3166-2 subdivisions and so is not listed. This implies that a tag like "[flag]001US" is valid (and equivalent to "US" spelled with RIS, which is preferred) but "[flag]001AI" is not valid. Is this intended? If not, can it be clarified? 5. Will any preliminary examples of CLDR 4-character subdivision codes be made available before any such codes are actually assigned? . The PRI #299 mechanism is clearly and intentionally oriented toward representing flags of well-defined geopolitical entities. Any proposal to extend the mechanism to cover the many other types of flags -- for historical regions, NGOs, maritime, sports, or social or political causes -- must be systematic and well-planned, not ad-hoc or haphazard, to assure interoperability and extensibility. The documentation for the PRI #299 mechanism should state clearly that (e.g.) the Confederate battle flag, the Olympic flag, the Esperanto flag, the LGBT rainbow flag, and the naval flags used to spell out "ENGLAND EXPECTS" can be represented only via a proper extension to the mechanism, not by ad-hoc means such as the use of unassigned or private-use combinations. This is at least as important as ensuring the stable coding of geopolitical flags. -- Doug Ewell | http://ewellic.org | Thornton, CO 🇺🇸
