For buyers contracting authority
Pick 72212214 when what gets built and accepted is the network operating system itself, the platform that runs and governs a network. The test is the deliverable: if the output is network OS software, this is the code; if it is an application, a portal, or a service that merely rides over a network, it sits elsewhere.
The line that causes trouble runs to the sibling 72212213, which covers enhancing an operating system that is already in place. Building the network OS as a new product is 72212214; extending an existing OS is 72212213. When the work is networking software but not specifically the OS platform, 72212210 (Networking software development services) is the broader home for it.
Because only 30 contracts have ever carried the code (TED 2009-2026), expect many authorities to file network-OS builds upward under the broader networking-software parent instead. Where a tender genuinely centres on engineering the network OS, hold it here; where the OS is just one component of a wider build, tag by the dominant deliverable.