Brandlines are public facing expressions of brand-ideas. They can be straightforward descriptions of what the brand does but a brandline is usually a good opportunity for richly layered and 'open' word-play within which the meaning of the brand can be read. Sometimes a brandline is also the brand-idea but this is less common. Successful brandlines have multiple meanings and offer additional insights into what experience a brand identity represents. And, at the same time, a brandline is itself an opportunity to provide a poetic aspect of the brand. Brandlines usually rely on other brand-marks to provide the context necessary for the intended meaning to be appreciated. In this sense they can be seen to form a useful part of a purposefully directed brand experience.
See examples of brandlines I have generated here.