Do you allow hidden links, no follow tags, or similar?

Unfortunately no, these are strictly against our Terms of Service.

http://www.backlinks.com/tos.php

Quote:"When a Publisher publishes Company text links, the code must not include any linking technique unreadable by search engine spiders. This includes using noindex/noarchive meta tags, nofollow tags, redirections, robots.txt redirections and cloaking methods. Sold text links must be visible on the Publisher pages at all times. Hiding these links or making them invisible is considered system abuse."

You can view this article online at:
http://www.whylink.com/kb/index.php/article/hidden-links-no-follow