Non so se esista una traduzione standard per "teaser" (anticipazione, apertura, ecc.). Quando a RL, posso solo supporre che significhi "right to left".

Not sure about the RL could it be "related link"?

There are basically two kinds of headlines:

1. The teaser headline which tries to pique the reader's
curiosity. The teaser headline serves as an intriguing
puzzle that can only be solved by reading the body copy.

2. The benefit headline which instantly promises a
solution to a real problem that the reader faces.

http://www.levison.com/january_2003.html