Any grouping of rods with the same character. For example, I have four 14' Ozarks, two B&M 14', one 12' B&M, one 12' Crappie Max, etc. That said, given equal bates and rigs each rod will act differently. That makes a windy day or light bite hard to judge.
I personally like the 14 Ozarks and will be going that way.. and will replace all others.