This is intended for secretaries and other staff making School Messenger calls/messages.
If you notice the number of contacts that will recieve the call/message is higher than the amount of students that is due to the targets setting.
Contact types can be Contacts (number shown in the SIS Student Profile), Associated Gaurdians ( parent/guardian numbers on the contacts screen in SIS), Both (combination of the two). If you were to select Contacts only you would find the number correctly matches the amount of students you have selected. It is not recommended to use this as no other numbers for that student will be called. If the parents are separated or the student is in another situation those additional contacts will not be called.
It is recommended you leave the Targets setting in the messages recipients section of New Broadcast set at the default Contacts & Guardians.