During registration of .SU domain names, registrar change, ownership transfer, or registration cancellation, as well as ID data change in the agreement, you will be required to submit to RU-CENTER:
You may check if you are identified in the "Manage your account" section → Contract → Update information
Copies of the requested documents could be submitted to RU-CENTER via:
Digital ID document copies can be submitted in .JPG, .PNG, .GIF, or .PDF formats. Attachment size should not exceed 10 MB.
In all cases you will be required to specify your contract number(s) or domain name(s).