In the Campaign Launch Schedule Webpage have an online documentation for "Current Crontab Entry".
May be it is not clear for a beginner, who doesn't know what a crontab is or how to create one in a command line, what to fill in this page. See the picture attached.
Having a "?" near the string "Current Crontab Entry" that link to the following online documentation (for example):
"This entry reflects what is filled in the entry form below".