The region and carrier lock. This is one of the most important segments.
This is a critical partition layout indicator. On the HTC One X, "S" often refers to the system partition layout or a specific hboot (bootloader) version compatibility. Some RUU variants have "S", "K", or "U" here to differentiate between WWE (World Wide English) and operator-specific builds. The region and carrier lock
Indicates the HTC Sense version (3.5, 4.0, 4+, etc.). In HTC’s internal numbering, "35" typically signifies Sense 4+ or a specific SKU for Sense 4.x on Tegra devices. On the HTC One X, "S" often refers
The software version number. HTC versioning follows a pattern: X.XX.XXX.X. Unlike OTA (Over-the-Air) updates
First, a definition. An RUU (ROM Update Utility) is an official Windows executable file distributed by HTC. When run, it communicates with an HTC Android phone in bootloader mode (usually via Fastboot) and flashes a complete, stock ROM image to the device’s internal memory.
Unlike OTA (Over-the-Air) updates, which only patch existing system files, an RUU performs a full wipe and rewrite. It restores every partition—boot, system, recovery, and radio—to the exact state HTC intended when they released that firmware version.
This is a signed, official stock ROM update from HTC that upgrades the HTC EVO 3D (GSM version) to Android 4.0.3 (Ice Cream Sandwich) with HTC Sense 3.6. It is intended for Taiwanese (Asia-TW) devices.