Spoilers are precisely defined here. Rules vary by the story's medium. Info from television stories can't be added here until after the top or bottom of the hour, British time, closest to the end credits roll on BBC One. Therefore, fans in the Americas who are sensitive to spoilers should avoid Tardis on Sundays until they've seen the episode.
The Doctor Who Magazine Winter Special of 1993 was a celebration of the 30th anniversary of Doctor Who. It was bigger than other issues of Doctor Who Magazine at that time, and included a retrospective on the entire history of the programme.