The example shown in http://hl7.org/fhir/search.html#uri is incorrect.
The explanation below says:
The second line performs a search that will return any value sets that have a URL that starts with "http://acme.org/fhir/".
Seems like :below modifier is missing and the 2nd item should have been
GET [base]/ValueSet?url:below=http://acme.org/fhir instead?
Also, can someone explain how :above modifier would work? The modifier section says the search term right matches the value so if I do something like
GET [base]/ValueSet?url:above=ValueSet/123 then it should match any URL that ends with ValueSet/123?