If you tag your links with appended strings and the appended string %%WA_MAILINGLEVEL_CODE%% is set at the organization level, you can enter a unique value in the Mailing Specific Parameter field at send time that is substituted in the string.

For example, you could enter a value, such as 2021 Sales Campaign or Back To School, that can be used for reporting on one or more emails in your site analytics. If you use Google Analytics, you can search for this value and it pulls up all reports that are associated with the value.