I am unlocked and rooted:Android version 4.0.3
Software number 3.14.605.12 71ORD
I'm wondering if this is true:
Android version=ROM and software number=RUU?
The software number is actually the firmware?
I'm thinking of putting in a custom ROM but want to make sure I can get back to stock.
If I go to shipped roms
Shipped ROMs the stock RUU is the file PH98IMG_ICS_3.14.605.12.zip and the ROM is PH98IMG_ICS_4.03.605.2.zip?
Does putting in a custom ROM change the RUU or leave the original there?
Thanks for any replies!
No, you don't understand how it works...
Android Version is exactly that, the version of the base Android operating system... it might be Gingerbread (2.3.x), Ice Cream Sandwich (4.0.x), or Jelly Bean (4.1.x/4.2.x/4.3.x). These version numbers are for the core OS, nothing more.
The "ROM" is the name of the ROM, the stock ROM is called HTC Sense, alternatives can be CarbonROM, Tachyon, BeanStalk, LiquidSmooth, and a host of others. This is just a name, they can be based on an assortment of Android versions as a base, then they each add their own special stuff. HTC Sense is nothing more than an relatively stock Android base, with HTC's own launcher and software added.
"RUU" is a term used for an HTC firmware image, it can be an EXE that is run from Windows (a true RUU), or a ZIP image that is flashed in Hboot (a PH98img.zip firmware image). These are signed by HTC and generally considered "official" although not always Verizon approved.
Software number is the HTC software image number (or part number so to speak), there are multiple ones, the current one is 4.5.605.14 and is based on Android 4.0.3 and has Global Mode enabled. 3.14.605.12 is also an ICS 4.0.3 based ROM but does not have Global Mode radios or firmware. 4.3.605.2 was a leaked firmware that was a predecessor to the current one. Third party ROMs use software numbers as well, although each uses their own scheme to do, such as Tachyon 1.2, CarbonROM 11062013, or LiquidSmooth 2.37
Some important things to note from what you said though:
1) You are on 3.14.605.12 firmware, this is old... You should upgrade to 4.5.605.14 if possible before playing with new ROMs as most current ROMs are all based on that firmware and radios. This is possible by accepting Verizon OTA updates 3.14.605.13, then 4.5.605.14. Or by installing the OTAupg.zip files, since you are already rooted, I would suggest going over to XDA and looking at the various threads by REV3NT3CH and asking him specificially how to go about, as I am uncertain in your current state. The reason to upgrade is your Hboot and radio firmware is out of date and for current ROMs it should be upgraded.
2) Installing a new ROM over-writes the current ROM, it will be gone and have to be reflashed if you install a new one to return to stock. Don't let the term "ROM" confuse you, in the Android world that is generally just the a distribution package, the ROM in your phone is just a collection of partitions that you normally can't read/write to unless you have root access, it isn't truly "Read Only Memory".
A few things to consider... once you are at 4.5.605.14, there is no RUU or software image to return to stock, although there is a step-up process if you are S-OFF, but for S-ON people there are mostly stock ROMs with a few minor changes, but for the most part unless you go S-OFF you will never be able to return to pure stock.