What does 1 Chronicles 15:18 mean?

and with them their brethren of the second degree, Zechariah, Ben, and Jaaziel, and Shemiramoth, and Jehiel, and Unni, Eliab, and Benaiah, and Maaseiah, and Mattithiah, and Eliphelehu, and Mikneiah, and Obed-edom, and Jeiel, the doorkeepers.

And with them their brethren of the second degree, Zechariah, Ben, and Jaaziel, and Shemiramoth, and Jehiel, and Unni, Eliab, and Benaiah, and Maaseiah, and Mattithiah, and Elipheleh, and Mikneiah, and Obed–edom, and Jeiel, the porters.

and with them their brethren of the second degree, Zechariah, Ben, and Jaaziel, and Shemiramoth, and Jehiel, and Unni, Eliab, and Benaiah, and Maaseiah, and Mattithiah, and Eliphelehu, and Mikneiah, and Obed-edom, and Jeiel, the doorkeepers.

And with them their brothers of the second order, Zechariah, Bani and Jaaziel and Shemiramoth and Jehiel and Unni, Eliab and Benaiah and Maaseiah and Mattithiah and Eliphelehu and Mikneiah, and Obed-edom and Jeiel, the door-keepers.

and with them their brethren, the seconds <FI>in rank<Fi> , Zechariah, Ben, and Jaaziel, and Shemiramoth, and Jehiel, and Unni, Eliab, and Benaiah, and Maaseiah, and Mattithiah, and Elipheleh, and Mikneiah; and Obed-Edom and Jeiel the gatekeepers;

And with them their brethren: in the second rank, Zacharias, and Ben, and Jaziel, and Semiramoth, and Jahiel, and Ani, and Eliab, and Banaias, and Maasias, and Mathathias, and Eliphalu, and Macenias, and Obededom, and Jehiel, the porters.

and with them their brethren of the second [rank], Zechariah, Ben, and Jaaziel, and Shemiramoth, and Jehiel, and Unni, Eliab, and Benaiah, and Maaseiah, and Mattithiah, and Elipheleh, and Mikneiah, and Obed-Edom, and Jeiel, the doorkeepers;