EFL Retained and Released player lists

I see that the EFL website has the lists, with the following comment; The information was correct as of 19th May 2018.
I have previously asked the following;
1) How do you add a player to a clubs latest squads list?
2) When are the lists updated, to remove players and staff who have been sold/released/sacked or finished their loans at a particular club?
3) Why are players/staff not removed/sacked,when a definite reference is provided?

Any chance that my questions are answered, as I would like to help and change club details, but cannot, when I am unable to add players/staff to a club who may not be on the on the database, but are definitely at a specific club.