Before continuing with this article, read Custom Fields.
Creating a dropdown custom field
When creating a custom field, choose the Dropdown option as the type.
Add each of your options in the Options section that appears. This list can be edited after you've created the custom field.
The label is shown to users and serves as a description of the option.
Value defines how the raw value of the option and will be included in any reports, exports or API usage. In the majority of cases, this will be the same as the label.
Using the dropdown
Similar to other custom fields, you can edit the custom fields directly from the applicable record.
The field will show as a dropdown and allow users to select any of the options you have defined.
Editing dropdown options
Once an option has been added, it's not possible to change its value; however you are still able to change its label.
If you wish to change the value of an option, you will need to delete it and re-add it. If the option has already been used you won't be able to delete it.