https://sn.1w6.org/file/clacke-20171130T030909-mp2f7gj.html

I've tried briefly finding, just on Wikipedia, where the standard table for romanization of Cantonese person names used in the Hong Kong government comes from. No luck.

It is *not* https://en.wikipedia.org/wiki/Hong_Kong_Government_Cantonese_Romanisation and also not https://en.wikipedia.org/wiki/Standard_Romanization_(Cantonese) .

All of the systems I can find on Wikipedia use either "z" or "j" for the initial /ts/, but when I registered my son's name, the tables of the person registrations office said it should be spelled with a "ch". (Their system sucks, I went with a Yale romanization.)

It is obvious to me that different parts of the government (land registry and persons registry) use different systems.