forms - Should field labels be nouns or verbs?

On a web form should field labels be nouns or verbs? This issue arose from two fields on an account request form that currently read:

• Temporary Password


• Re-Enter Temporary Password

There is debate as to whether a verb should ever sneak in. From general observation I believe nouns are more frequently used - especially for sign-up forms - but I do know that breaking a pattern can draw attention to the item.

So, nouns or verbs (or both)? Links to studies would be greatly appreciated.