If you are a Chain of Custody or Forest Management Certificate Holder, you are already authorized to use the FSC trademarks. Trademark use is managed by your Certifying Body or if you are in a Group Certificate, your Group Manager.
If you are certified and have a question about trademark use, contact your Certifying Body or your Group Manager directly.
For the full trademark standard, which lays out all requirements for use of the FSC trademarks by Certificate Holders, see FSC-STD-50-001 V2-0. And for an overview, see the Quick Guide on Trademark Use for Certificate Holders.