Britsimon
Super Moderator
I think it is a standard requirement in some of the former Soviet Union countries. Also I know of one person from an African country who was asked to provide one because they couldn't provide enough evidence to satisfy the consular officer.
Yes, we are short a document due to local official delay but they kept our passports and said they would issue the visas when we send the document.
Congrats on your interview SusieQQQ