castrox

I was just wondering if anyone had any thoughts on what needed to be done to phone systems (PBXs, phones, etc) in order to be sure no data (phone numbers, contact information, asset tags, etc) were left on them. I am not an expert on these things and really dont know if this is even a concern - the company I work for resells these sorts of things and some contract we have say we must remove any identifiable information. Equipment we receive varies from old stuff to nearly brand new, so its impossible to say exactly what this will apply to, but if you could just give me an idea of whether or not this should be a concern, thatd be great.

Thanks
-C