Format dvd/cd for use in Windows

Hello! I was asked to 'format' dvd-rw to be used in Windows. I am actually new to Mac OS: the only thing that I found was 'Clean' command in the Disk Utility. Seemingly after cleaning Mac can write (burn) to the dvd; and the burned files (as I understand) will be readable in Windows. However, I do not have to burn any files onto the dvd; I have to return the dvds back clean and fully ready to be used in Windows. Windows see the dvd which I 'cleaned' in Mac OS but cannot burn any files to the dvd (says the dvd is not writable). Is there any method or utility to "format" dvd-rw in Mac OS to make them ready for Windows? Thank you in advance!

If the discs are to be blank, then you don't have to do anything to the discs.
Whoever asked you to format them doesn't seem to know what they are talking about.

Thank you, but I am stuck then. Windows does not write anything to the DVD cleaned with Mac OS Disk Utility: says 'not supported disk format'. Do I make a mistake somewhere?