This is from last week's China - TRQs panel report:
6.18. The United States requests that the term "contracting party" be replaced by the term "Member" in paragraph 7.187.120 China has not commented on this request. We note that the term "contracting party" appears as part of a quote from Article XIII:3(a) of the GATT 1994. Paragraph 2(a) of the Explanatory Note to the GATT 1994, provides that "references to 'contracting party' in the provisions of GATT 1994 shall be deemed to read 'Member'". We therefore do not consider it necessary to modify the quote in paragraph 7.187, and reject the United States' request.
This is based on my general sense, rather than actually looking it up for the purposes of this blog post, but it seems like there is a difference in approach, with the Appellate Body usually using "Members" and panels usually using "contracting party" (and sometimes recently, "[Members]"). I wish someone in the WTO Secretariat would find a way to harmonize this, but I guess it is difficult to get the different divisions on the same page.