Informational lines serve multiple purposes, but in general, you cannot use our spaced repetition system to learn them because the course creator has deemed the line unnecessary to fully commit to memory as it may create confusion if you did.
Informational lines can be lines in which an alternative move can be played in a position, and the consequences are worth looking at, as they impact the general theory of the opening., However, the author recommends another main line and has not deemed the alternative important enough to mark it as an alternative.
Informational lines can be lines that are common mistakes or subpar moves, and hence the course creator wants you to be aware of them but does not want you to learn the mistakes, as you may confuse them in a real game situation.