回複：美國境內F1轉的H1，現準備到境外返簽H1, 也有名額一說嗎？

You have the H1 approval from USCIS, which means you have used a number.
Unlike F1, J1, or B visa (you don't need USCIS approval for those before you can go directly to consulate), but you must have H1 approval notice before your H1 visa interview.