1. It's TERBites.
2. Go to desired thread
3. Highlight address in address bar
4. Hold down the CTRL key (bottom left of keyboard, below SHIFT)
5. While holding CTRL key, press the letter C (between X and V on the keyboard. Note it doesn't matter if it is capitals (big letters) or lower-case (little letters))
6. When composing your email, again hold down the CTRL key (see above to find it again) and depress the letter V (this one's between the C and the B)
7. When your recipient gets the email, and either clicks on or cuts and pastes the link you sent, they'll go straight to the thread mentioned in # 2 (above).