You might be wondering: "What's the difference between groups and tags?"
Groups are inclusive in that the message sends to anyone with any of the selected groups.
Tags are exclusive in that the message will go to only those with all of the selected tags.
Filtering with Tags
For example, at XYZ University, we have 4 groups: North, South, East, and West campuses.
We have our subscribers "tagged" by their role at our university: Faculty, Staff, and Students.
If I wanted to send an Omnilert message to the students at NORTH and WEST campuses only, here's how we do it:
Step 1: Select Groups
First, we select the "North Campus" and "West Campus" groups:
This will send to anyone who is a member of either (or both) groups:
"Select subscribers that are in North Campus or West Campus groups..."
As you may have guessed, that could be a lot of people, as it'll send to everyone in either group.
Step 2: Select Tags
However, we want to send to just "students"... so we can select tags to filter the recipients by their role at the university.
Since we want to sent to just students, we select the Students tag:
So, now our selection is:
"Select subscribers that are in North Campus or West Campus groups, and have the Students tag"
As you can see, selecting a tag will further filter our sending down to just those with the relevant tag who are in any of the selected groups.
Since we've used tags to filter our message, we can proceed and send our message and it will go to the intended audience: Students at the North and West campuses only.