This website contains age-restricted materials including nudity and explicit depictions of sexual activity.
By entering, you affirm that you are at least 18 years of age or the age of majority in the jurisdiction you are accessing the website from and you consent to viewing sexually explicit content.
Commenting/making posts has always required an account of some sort, at least as far back as I can remember. Maybe the IRC days you just needed a name
With guestbooks - not always. They were full of spam, of course