Although the interface for creating project fields allows a drop down field to be set as a required field, the actual use of the field allows the field to not be required.
I have tried creating custom project fields as drop downs, but if the user skips over the field a default is chosen. And if a default cannot be avoided, how is it really a required field (requiring the user to make a conscious choice)? If a radio button format is used, a default choice can be avoided by choosing a blank choice as the default when creating the field. Choosing a blank choice for a drop down field when creating the field is not allowed.
AEG