If you have the item in your possession, you can trade it.
There are, however, some things to keep in mind that are against the rules:
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Do not offer fg/items you don't have.
and
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Do not advertise items not directly for sale via d2jsp. This includes advertising an item that is on an auction house within a specific game.
- As stated, the item must be on your character or otherwise in your possession to offer it up for trade. (taken from
Trading Rules)
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No advertising or linking to any external site that has not otherwise been expressly authorized. This includes mislabeled or deceptive links (including tools to shorten or obfuscate a link).
- Linking to outside sites without prior approval is a against the rules, including shop and real-money sites.
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No monetary sales of anything on, from, or through this site, including, but not limited to: accounts, virtual goods, forum gold, CD-keys.
- The items can only be traded here for forum gold or other items.
Taken from
Site Rules