(S-90) When acquiring telecommunications services using the Inquiry/Quote/Order (IQO) process or Communication Service Authorizations (CSAs), refer to the Procurement Guide for Telecommunications and the IQO Acquisition Deskbook located at https://www.ditco.disa.mil/ .

(S-91) A CSA modification may be issued unilaterally if an equitable adjustment in contract/order price or delivery terms has been agreed upon and documented in advance (e.g., quotation, completion notice/report, bilateral modification to IDIQ contract). If an equitable adjustment in contract/order price or delivery terms has been agreed upon and documented in advance, only the unilateral CSA modification is required. The contractor shall acknowledge the modification as required by the contract.