1. Field name - your field label.
2. Type - select type of the field. If you need email type, click on Email in a drop-down list.
3. Page section/Admin tab - place your new custom field to appropriate section.
4. Mandatory - if you enable this option, the new custom field will be a required one.
5. Search support - activate it if you need to include this field to search tool.
6. CSV import - activate if the field must be included in CSV import template as well.
7. RETS support - do not touch it if you do not have Premium version installed!
8. Visible for - hide specific fields from specific users.