You can add tags to your contact list in Mailchimp

Now Mailchimp allows you to segment your contacts with tags that will help you identify them through data that only you know. These labels are 100% customizable, so you can assign them as you prefer to organize your contact lists.

This information will only be known to the administrator of the account, which means that your client will not be able to access them. Through them you can organize your database and even highlight some key customers that you want to consider.

How to do it?

The tags can be placed from the general contact list, from the individual profile of some of them or added at the moment of importing the contacts.

How to see them?

In the main list, you will see a tab that will indicate the label (s) that your contacts have. In that same place, you can make filters to segment them according to the search you are doing.

This new option adds a lot of value to your brand because it will allow you to reach more specifically each of your current or potential clients.

We see how strategies to personalize marketing actions are developing more and more, with the intention of offering specific messages for each type of customer.

Source: https://mailchimp.com/en/help/getting-started-tags/