Originally, Joss Whedon didn't want either of Buffy's parents to appear as characters on the show. Accepting that that could get complicated, he settled on just having her mother, Joyce, appear in a nearly regular role, while Buffy's father Hank appeared in very few episodes.
Mayor Richard Wilkins:
Well, what a day this is. A special day. Today is our centennial - the 100th anniversary of the founding of Sunnydale and I know what that means to all you kids... not a darn thing. Because today, something much more important happens - today you ...
In nearly every episode presented in widescreen, there is crew/equipment visible and/or revealing mistakes. This is because the series was originally shot for 4:3 frame and these issues would not have been visible as the show was originally intended to be presented. As such, one should take much of the goofs reported on episodes as being conditional on applying only to the widescreen alternate version.
For the three first season 6 (the first UPN season) episodes (Bargaining parts 1 and 2, and Afterlife), the ending credits had almost 3/4 parts of the screen occupied by the Buffy logo (as seen on the opening with the moon behind), and the credits appearing under it. This was later returned to the normal black screen with the credits.
The DVD versions of the 2nd part of most two-part episodes omit the opening recap of the previous episodes. The US DVDs omit the recaps on all episodes.