'Virus-free' declaration

[Erika Yanovich]

Hello Whirlers,
Customers asked us to declare that the CDs accompanying our products
(documentation) are virus free. They haven't been able to send me an
example of declarations from other vendors they are happy with, and need
no particular wording. This doesn't seem such a big task, still some
examples could help. The more important question is how is one supposed
to make sure the CDs are virus free? Is there any 'standard'? Should
they be checked with an anti-virus app? They contain a GUI and some PDF
files.
TIA
Erika