Facebook Inc. disclosed its letters with the Securities and Exchange Commission in regulatory filings Friday. They show the back-and-forth between Facebook and the SEC on issues such as Facebook’s purchase of AOL patents from Microsoft Corp. and its pending purchase of Instagram. Regulators also wanted to know what it means that CEO Mark Zuckerberg controls Facebook.

The filings are a usual part of the IPO process. They are confidential at the time, but are released after about 30 days following the IPO. Facebook’s stock is down about 24 percent since it started trading in May.