Yes. That is it. Not "Tuna Sandwich" with capital letters, not "tuna," not "grilled tuna." The precise string is: tuna sandwich (all lowercase, no quotes).
While not a secret "feature" of the site code, cross-seeding scene releases from other trackers is often called an "Easter egg" strategy by the community because it allows for massive upload gains with zero download "cost" on the TL account. How to Unlock Site Secrets torrentleech easter egg
TorrentLeech’s Easter Eggs, real or imagined, serve a psychological purpose: real or imagined
Here is the catch—and the reason this easter egg is so legendary. torrentleech easter egg
: Logged-in users can find a hidden calendar link on the homepage. Opening a "door" each day reveals a gift.