Totally stuck on Sublime Temptation pattern

Hi please can any one help , the pattern says to work a wrap row on boarder of cardigan every 6th row , anyone know why it would ask this ? , its a moss stitch boarder very confused


Sometimes this is called for when the pattern in the sweater and the pattern in the border don’t have the same row gauge. If you add in an extra row every so often in one of the stitch patterns, it’ll prevent puckering or ruffling.

Thank you so much Salmonmac , that makes perfect sense . I was at a full stop as thought I was reading it incorrectly , will pick it back up now