Ambiguous Label for "Additional" Field for Second Line of Street Address

If the address input fields are used in the middle of a number of other fields, I would not want to put them in a fieldset. Consider, for example, the sequence of a company name, then the address, then the telephone numbers.

Unfortunately, if the address input fields are not within an "Address" fieldset, the "Additional" field label is very ambiguous.

I believe the normal mode is use Street 1 and Street 2 or Address Line 1 and Address Line 2.

I know I can change this label on a given site without much effort, editing the module directly or doing a form alter in my theme, but I would suspect other users of this module would appreciate the change. Any thoughts?