Something to the effect of:
If you wish to report a comment in your journal which you feel is unsolicited advertising, select the checkbox marked "Mark this comment as spam" when you delete the comment. This automatically reports the comment to LiveJournal administrators who are watching for widespread or repeated comments which contain unsolicited advertising.
To report an entry in a community that you maintain, follow the instructions for deleting an entry using the web interface [link to FAQ 2] and select "Delete and Mark As Spam" rather than "Delete Journal Entry". If you are not the maintainer of the commmunity, you will have to contact the maintainer.
Please do not use the spam reporting interface to report comments or entries which are off-topic, harassing, or that you feel are violations of the Terms of Service but are not spam. This system is used solely for identifying users who are using LiveJournal to advertise services or products in journals where such advertisements are not desired, and any reports which are not unsolicited advertising will be closed immediately. You can report other violations of the Terms of Service following the instructions located at [FAQ 105]".
Perhaps also mention somewhere in 105 that spam reporting should not be done through the Abuse Form, but rather using the interface?
Also, the title (which is already ungodly long) should probably have something along the lines of "How do I report spam?" tacked onto the end of it. The alternative to this is that spam-reporting gets its own FAQ and is linked from 105 and 197.