24 May 2005: Conventional wisdom.

Rounding up some reasonably authoritative links on current best practices in Trackback spam prevention:

  • Learning Movable Type: Trackback spam (Feb. 2, 2005). Techniques mentioned:

    • content-based filtering (the obvious approach, inspired by email anti-spam techniques)
    • obfuscation (juggling the the TB URL as well as nearby text; more examples here)
    • blacklisting (ignoring known spam IPs)
    • expiration (turning off TBs for old posts)

    Plenty of additional links at the end of the article.

  • Matt Mullenweg: Trackback spam (Jan. 5, 2005). The original post isn’t much, but the discussion (in the form of comments, and, yes, trackbacks) offers a pretty good look at current best practices (geared toward WordPress users). Add to the above list of techniques:

    • moderation (simply involve a human for every comment or TB received)
    • whitelisting (remembering “known good” URLs, as pointed out by Matt in the comments; see the 1.5 announcement for more info)
  • WordPress wiki: Trackback Spam Tools/Plugins.