The parser does not accept left parenthesis after USING clause. The generative AI model I use for generating SQL queries keeps adding parentheses.
Example:
SELECT * FROM ? a JOIN ? b USING (c)
SyntaxError: Parse error on line 1:
... ? a JOIN ? b USING (c)
-----------------------^
Expecting 'LITERAL', 'BRALITERAL', got 'LPAR'
This fiddle shows the details.