Yeah you can say you will rank them or like the program, but not that they are your number 1. In their official rules: "The program(s) may freely discuss any matter with an applicant, and each may express a high level of interest in the other. A program may voluntarily inform an applicant as to whether or not it intends to rank the applicant, and an applicant may voluntarily inform a program as to whether or not the applicant intends to rank the program. However, neither party (program or applicant) may solicit such ranking information from the other party. In addition, neither party may disclose to the other party or solicit from the other party any information regarding the positioning of any applicant or program on a Rank Order List. Furthermore, any expression of interest or intention to rank made during the free discussion between a program and an applicant is subject to change based on further considerations. Both the program(s) and the applicant(s) have the right to change their Rank Order Lists at any time prior to the Rank Order List deadline."