 Many allow vendors to sign up at no charge to receive e-mails of requests either generally or for specific categories of product or service for which there is an interest.In some cases, the entire process is done on-line with responses as scanned documents or PDF files uploaded to the server; in other cases, or for legal reasons, a response must be sent in hard copy form and/or on CD/DVD disc or flash drive by mail or delivery service.The suppliers have to return the bidding by a set date and time to be considered for an award.