[greenyoda]

More precisely:

Articles killed by user flags will have either "[flagged][dead]" or "[dupe][dead]". Comments killed by user flags will also have the "[flagged]" designation.

Articles that have only "[dead]" were killed either by a moderator, or by the site's software (e.g., due to the user or the domain being banned).

An article can be marked as "[flagged]" but not "[dead]" if it was killed by user flags and later revived by users (using the "vouch" function).

Dead articles won't be displayed unless you're a logged-in user who has "showdead" enabled in your profile.