When defining a field style, if you leave the Value field blank, the style is presented only in the form view instead of both the form view and list view.
Steps to Reproduce
Log in to a demo instance.
Navigate to System UI > Field Styles and click New.
Create two new styles with the following values, and click Submit after creating each one.
Field name: number
Field name: caller
Value: <Leave blank>
Check the fields in the list view and the form view and note that the list view style is applied only when the Value field is populated.
Within the field's Style text box, insert a simple default line of CSS code like the following example:
Related Problem: PRB606723