All About Anti-002
Short story: you don't know what this option means, you don't need it, and it will make some games not work properly if you use it.
Long story: OK, hopefully a little history lesson should clear things up.
When rev 13 of IOS249 came out, it no longer did a certain patch and 002 errors started popping up in loaders. Within hours, WiiPower had told everyone the line that needed to be added to loaders to replace the old patch. Cfg had that patch in and was working almost immediately and most of the other good loaders were updated too (but not all). Cfg did that choice in a mandatory way. GX decided to make an option that was disabled by default. While all this was happening, Waninkoko also released a rev 13b that included the patch back in to shut up all the guys that were screaming about 13 not working.
This created a lot of confusion and misinformation. People thought 13b must be better than 13 (which people started calling 13a) because it came out later. However, the IOS-patch was beginning to fail in games where the loader one would work. Rev 13 was the much better revision and simply worked with everything in Cfg (and with GX if you turned on the 002 patch). It was also discovered that some games would fail if both the loader-based and IOS-based patch were applied simultaneously. Thus, loaders started to implement an "anti-002 fix" for these people that were not using rev13 that allowed the loaders using the better patch to still use the older IOSes and rev 13b.
Thus we come to where we are now:
USB LoaderGX has a global 002 fix that is off by default and you need to switch it on if you are using rev13-rev17 (but not 13b).
Configurable USB Loader on the other hand, patches 002 no matter what and provides an anti-002 fix for those guys on old IOSes. If you are on one of the later IOS249 revisions, or using IOS222/223, then you should never need to turn this option on. In fact, turning it on when you have an IOS that doesn't need it has been known to cause runtime errors.