In the Address Book, you can further customize organization of your contacts by creating tags. For example, I have created a “SanFrancisco” tag to apply to some of my contacts so I can search for them quickly by specific location. There are no rules here; you can make as many tags as you want for a contact, and they can say anything! Here’s what making a tag for a contact looks like:
Click on the contact and scroll down to tags/groups and add what you want your tag to be. You can then add other contacts by following the same process.
Then you can look under Tags and the contacts with that specific tag will appear:
Here is how to search by other parameters: