Comment Lockdown is a drug of last resort in battling comment spam. You should not use this if you haven't tried something less likely to cause side effects like Mollom. You should continue use of Mollom with Comment Lockdown. This module has some very specific rules for comments, and unlike Mollom, is incapable of learning, has no settings, does not care what kind of user you are, and rejects anything written in a language other than English.
These rules aren't arbitrary; they're based on experience with The New York Observer's massive database of spam comments. This module won't help sites that accept comments in languages other than English.
- Link (A) tags cannot account for more than 20% of all characters.
- No more than 20% of all characters can be non-ASCII--this accounts for words like "fiancé" while preventing comments in other languages.
- At least 10% of all words must be in the list of top 100 English words.
These rules are currently not flexible. If interest develops in this module, I might consider allowing admins to tweak thresholds, disable the JS checker and add role-level permissions for it.