Hi Andy,
I hope that you are talking about the current SCWCD...
If so, there is no objective about filters and you don't need to read them, if you are doing the current SCWCD... But if you are on your way to the beta version of the new SCWCD, then there is an objective about filters.... So you have to read them carefully, since it's a new added objective....
Co-author of SCMAD Exam Guide, Author of JMADPlus
SCJP1.2, CCNA, SCWCD1.4, SCBCD1.3, SCMAD1.0, SCJA1.0, SCJP6.0