I have some publications in Elsevier and Springer journals. After publication, I received an author's personal copy of one of my articles. I don't know how they sent it to me because I don't remember ever had requesting a personal copy. After that I did not receive any personal copy for any of my published articles. Lately, I had a conversation with my supervisor and he asked me to provide him the author's personal copies of my published papers as I was the communicating author. He told me that the author's personal copy is mandatory for official use.
I could not understand that. How could the author's personal copy be anyway different from original copy for the purpose of official use?