Custom fields (also called profile fields) store information about your contacts beyond the email address — names, company details, locations, preferences, and any data specific to your business. You manage them under Lists → Custom Fields, and the values power personalization merge tags, segment filters, and import mapping.
Mumara ships with default fields (First Name, Last Name, Birth Date, City, State, Country, Zip Code, Mobile, Phone, Fax, Company, Title), and you can create your own with Add New. Each field has a name (must start with a letter; letters, numbers, underscores, and spaces only; unique), a group, a display order, a required flag, and a type: Text, Numeric, Multiline Text, Checkboxes, Dropdown, Radio Options, or Date. Selection types need a list of values entered one per line — commas aren't allowed. A field must be assigned to a contact list before contacts in that list can hold values for it.
Use fields in emails as merge tags like %%first_name%%, and in segments with type-specific operators (Contains, Greater than, Month of year for birthday campaigns, and so on).
Worth knowing: a field's name can't be changed after creation; unassigning a field from a list permanently deletes that field's data for those contacts; marking a field as Default only affects newly created lists; and if a merge tag isn't rendering, check the %%field_name%% format and that the contact actually has a value.
