The word "codenamed" is correct and usable in written English.
You can use it when referring to something that has been given a name temporarily or secretly. For example: The new project, codenamed Project Phoenix, is set to be released next month.
The UK has a similar programme, with both codenamed after civil war battles: Bullrun for the NSA and Edgehill for GCHQ.
Recently, the company launched the latest release of its OS X operating system, codenamed Mavericks.
A separate contingency plan, codenamed Operation Halberd, to use troops in the event of a dock strike, had also been drawn up.
The CIA began the establishment of a specialised detention centre, codenamed DETENTION SITE COBALT, in April 2002.
The secret police files, codenamed Gorilla, featured wiretaps of leading financiers meeting discreetly with centre-right governing politicians to trade government tenders for cash.
It is to be replaced with a much more limited EU "border protection" operation codenamed Triton run by Frontex, the EU's external border agency, which will operate within 30 miles of the Italian coast and will not conduct search-and-rescue missions.
In the aftermath of the kidnapping, Israel launched an operation codenamed Brother's Keeper, during which more than 400 Palestinians – mostly Hamas members and supporters – were arrested in the West Bank and at least five were killed.
Philip Morris's covert 10-year strategy, codenamed Project Sunrise, intended to "drive a wedge between various anti groups" and "position antis as extremists".
He was detained for a story he wrote in 2010, based on (literally) a suitcase of military documents, handed over to him by a whistleblowing officer, which implicated senior commanders in an attempted coup d'état, codenamed Sledgehammer.
Using a programme codenamed Tempora, it can store and analyse voice recordings, the content of emails, entries on Facebook, the use of websites as well as the "metadata" which records who has contacted who.
Instead of the Italian operation, a limited joint EU "border protection" operation, codenamed Triton and managed by Frontex, the European border agency, is to be launched on 1 November.
