You can give lines the same name and then use the span keyword to target lines of a certain name. This is really useful if you want to create a complex grid with multiple content tracks and gutters.
I have made a slightly larger grid here and have named all of the Grid Lines before the content tracks with
col and all of the lines before the row tracks with
row. I can then start at a certain column line by using
col <line number> and span by saying
span <number of lines>.