Making XML schemas work was often a hassle. You have a schema ID, and sometimes you can open or load the schema through that URL. Other times, it serves only as an identifier and your tooling/IDE must support ID to local xsd file mappings that you configure.
Every time it didn't immediately work, you'd think: Man, why don't they publish the schema under that public URL.


Currently standing at $700k.
Regarding the model: