Referral links can be used but only in signatures and not in posts and they should not be hidden, and there are no exceptions.
Read full Forum rules here:
Forum rules
1. No zero or low value, pointless or uninteresting posts or threads. [1][e]
2. No off-topic posts.
3. No trolling.
4. No referral code (ref link) spam. [1]
5. No link shorteners that require users to view an ad.
6. No linking to phishing or malware, without a warning and a valid reason. [e]
7. No begging. [5]
8. No threats to inflict bodily harm, death threats.
9. Discussions in the main boards must be in english. All other language discussions should be posted in the appropriate Local board.
10. No embedded NSFW images anywhere. NSFW content must be marked accordingly.
11. No linking to illegal trading sites.
12. No duplicate posting in multiple boards (except for re-posting it in the local language boards if it's translated).
13. Bumps, "updates" are limited to once per 24 hours per thread. Bumping multiple threads at the same time is allowed if it's not annoying. [2][e]
14. All altcoin related discussion belongs in the Alternate cryptocurrencies and it's child boards. [3][4][e]
15. No on-forum altcoin giveaways. [6][e]
16. Do not have more than one active sales topic in the Currency exchange board. [3]
17. Trading of goods that are illegal in the seller's or buyer's country is forbidden. [2]
18. Having multiple accounts and account sales are allowed, but account sales are discouraged.
19. Possible (or real) scams and Trust ratings are not moderated (to prevent moderation abuse).
20. There are restrictions when selling accounts and invites for invite-only sites. See https://bitcointalksearch.org/topic/sales-of-accounts-and-invites-to-invite-only-sites-134779 [2][?]
21. Old bumps should be deleted. [2]
22. Advertising (this includes mining pools, gambling services, exchanges, shops, etc.) in others threads' is no longer allowed, including, but not limited to, in altcoin announcement threads. [8]
23. When deciding if a user has broken the rules, the staff have the right to follow their interpretation of the rules.[e]
24. Advertisements (including signatures within the post area) in posts aren't allowed unless the post is in a thread you started and is really substantial and useful.[9][e]
25. Ban evasion (using or creating accounts while one of your accounts is banned) is not allowed.[e]
26. Local thread rules, if stated properly when the thread was started, specific enough and don't conflict with the forum rules, have to be followed.[e]
27. Using automated translation tools to post translated content in Local boards is not allowed.
28. Exploiting bugs or flaws (even if the result is harmless) in the forum's software is not allowed.
29. Sending unsolicited PMs, including but not limited to advertising and flood, is not allowed.
30. Similar marketplace items must be listed together.[2][e]
31. User avatars must not contain NSFL or NSFW content, infringe on copyright or attempt to impersonate a user.[10]
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.
33. Posting plagiarized content is not allowed.[e]
and then posted here, in case moderators delete or move his topic to trash.
