analysis and testing performed by security experts is reasonable evidence in this direction), but there is little or no published evidence to support that assumption. Impact on cost and schedule In 2006, the US Government Accountability Office published a report on Common Criteria evaluations that summarized a range of costs and schedules reported for evaluations performed at levels EAL2 through EAL4. In the mid to late 1990s, vendors reported spending US$1 million and even US$2.5 million on evaluations comparable to EAL4. There have been no published reports of the cost of the various Microsoft Windows security evaluations. Augmentation of EAL requirements In some cases, the evaluation may be augmented to include assurance requirements beyond the minimum required for a particular EAL. Officially this is indicated by following the EAL number with the word augmented and usually with a list of codes to indicate the additional requirements. As shorthand, vendors will often simply add a "plus" sign (as in EAL4+) to indicate the augmented requirements. EAL notation The Common Criteria standards denote EALs as shown in this article: the prefix "EAL" concatenated with a digit 1 through 7 (Examples: EAL1, EAL3, EAL5). In practice, some countries place a space between the prefix and the digit (EAL 1, EAL 3, EAL 5). The use of a plus sign to indicate augmentation is an informal shorthand used by product vendors (EAL4+ or EAL 4+). References External links CCEVS Validated Products List Common Criteria Assurance Level information from IACS Cisco Common Criteria Certifications IBM AIX operating system certifications Microsoft Windows and the Common Criteria Certification SUSE Linux awarded government security cert XTS-400 information Understanding the Windows EAL4 Evaluation Computer security procedures Evaluation of computers Management cybernetics de:Evaluation Assurance Level