A previously unseen version of Android 4.4 KitKat has been discovered on Google’s Chrome bug tracking board by Myce who spotted build KTU65 running on a Nexus 5 in an issue description that was initially labeled “Google Restrict View” – or visible only to Google employees – before being made public.
“According to the convention the first letter is the codename of the release family (e.g. ‘K’ for KitKat). The second letter is a branch code that allows Google to identify the exact code branch that the build was made from, and ‘R’ is by convention the primary release branch. The next letter and two digits are a date code,” Myce writes. “The letter counts quarters, with ‘A’ being Q1 2009. Therefore, ‘F’ is Q2 2010. The two digits count days within the quarter, so F85 is June 24th, 2010. Finally, the last letter identifies individual versions related to the same date code, sequentially starting with ‘A’; ‘A’ is actually implicit and usually omitted for brevity.”
Thus, it’s easy to determine that build version KTU65 describes a KitKat version dated March 6, 2014. It’s not clear when the next KitKat update is coming, but it certainly looks like Google is working on one. Also, it’s not known what the update would bring, but it may possibly fix Nexus 5 camera issues and other bugs once Google releases it. The latest KitKat build available to users is KOT49H, or Android 4.4.2.