A filing with the Securities and Exchange Commission (SEC), also known as the Registration for Depository Shares form, required for private foreign companies who wish to have shares of their company trade as American Depository Receipts (ADRs). SEC Form F-6EF must include the issuer's foreign name, its name translated into English and the contact information for the U.S.-based depository issuing the ADRs. Taobiz explains SEC Form F-6EF Form F-6EF is almost identical to Form F-6, which also registers ADRs with the Securities and Exchange Commission. However, the "EF" designates that this form is "auto-effective" upon filing, meaning that the SEC considers the securities registered upon receipt. Related forms: SEC Forms F6, 15, 18 and 20.