[Samsung Galaxy Note 8 Guides, News, & Discussion] Mr. Orange 645:
For simplicity sake, NO discussion of the leaked "D" builds. This thread is ONLY for the official beta z builds

Here is a guide I made that helps you figure out which version of Android you're running or downloading

You can tell what version of Android it is just by the build number. You can also tell if each update just contains the updated security patch, or if new features were added or updated.

The first part of the build number never changes. It will start with your model number (N950U or N950U1) followed by a region code for your model number (UE for US unlocked or SQ for US carrier models). After that, there is a 5 character build number that changes with each version.

The first character (S or U) tells you if it's a security patch or a feature update. S = Security Patch and U = Feature Update (features added or changed)

The second character (a number) tells you bootloader version. This is important to know when upgrading and downgrading OS versions. You can NOT downgrade the bootloader. 1 = Bootloader V1, 2 = Bootloader v2, etc...

The third character tells you the Android version. This is different for each Galaxy device. A is the Android version that device was released with. (For the Note 8 A=Nougat; B=Nougat with updated bootloader/carrier switching; C=Oreo, D=Pie) Z is for official Samsung BETA program builds.

The fourth character is the year of the build (R=2018, S=2019). This is the same across all Galaxy devices.

The fifth character is the month of the build. This does not indicate what security patch it contains, only what month it was built. (A=January, B=February). Again, same across all Galaxy Devices.

The sixth character is just the sequence of builds that month (1-9, then A-Z)

So, official Oreo build S5CRG9 is:

S - Security Patch

5 - Bootloader V5

C - Oreo

R - 2018

G - July build

9 - 9th build in July

and leaked Pie build U5DRL7 is:

U - Feature update

5 - Bootloader V5

D - Pie

R - 2018

L - December build

7 - 7th build in December

and official Pie beta build U5ZSAB is:

U - Feature update

5 - Bootloader v5

Z - Official Samsung BETA program build

S - 2019

A - January build

B - 11th build in January

So let's break down my current build number, N950U1UEU1ZSAB

N950U1 - Build is for the Factory unlocked U1 model

UE - Region code US Unlocked

U - Feature update

5 - Bootloader v5

Z - Official Samsung BETA program build

S - 2019

A - January build

B - 11th build in January

Always make sure you know what bootloader version comes with each build before you flash it. This is especially important with the leaked builds. If you flash a leaked Pie build, and it is already updated to bootloader V6, you will be stuck there, which will really suck if its a buggy build.

As of right now, if you update to either the leaked Pie builds, or the official beta build, you can easily downgrade back to Oreo using patched ODIN. Just repeat the steps in the OP. But once Samsung updates the bootloader to V6, most likely after the official release of Pie, you won't be able to downgrade.

NOTE: If you decide to downgrade back to Oreo, you will need to do a factory reset first. Otherwise you'll get a bootloop after flashing Oreo.