infrastructure as code(is the management of infrastructure (networks, virtual machines, load balancers, and connection topology) in a descriptive model, using the same versioning as DevOps team uses for source code. Alex_Odeychuk)
formal requirement(formal requirements for virtualizable third generation architectures — формальные требования к виртуализируемым архитектурам третьего поколенияAlexander Demidov)