Add the run information
With this form you put put in the first issue and the last issue of the run. You can repeat this as many times as you need to for a given title.
If you add a run that is wrong, just select it and click delete.
There is no known limit to the number of runs that can be added at one time. I'm sure there is one but if so, its a limitation of the language and not the software written in it.