Rules list for the marketplace-ONLY-
No trading real-life items or money for in-game items (or the other way around), unless it is a donation for the server under the "donation" section.
No trading Runescape accounts for ANYTHING that involves R3ap3rscap3 unless it is supervised by a staff member and a second staff member knows about the transaction.
No selling r3ap3rscap3 accounts or promotions, unless you have discussed it with Peoplereaper ("Admin" on forums).