You can bid in that exact order, and as your seniority allows you to move to the next thing on your list. So your bid might be any captain. Then ord line, mke line, ord res, mke reserve, iad line, iad res, then cae line and reserve. When you get hired you might only have the seniority to hold cae reserve which you will be stuck with for a month or 2, then once you have enough seniority you will jump up to mke reserve then ord reserve, then mke line and finally after about a year ord line.