diff --git a/README.md b/README.md
index 2aa9dee..9101015 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,58 @@ This is a Python script originally created by [thurask](https://gist.github.com/
 GIST](https://gist.github.com/thurask/f4ace564e6575ef41c4e35d2458ca2d0)) to check for update files
 for a BlackBerry KEYone phone. It tries to emulate the requests done by the "Updater" app or the
 "Mobile Q Loader" firmware updater.
+
+
+What is a FOTA/OTA?
+-------------------
+
+(F)OTA = (Firmware) Over-the-Air
+
+OTAs are differential(!) updates for a specific firmware version to a newer one. To install it,
+you **must** have the correct initial firmware installed. Otherwise, the updater script will fail
+and abort the update.
+
+
+How to find available OTA updates
+---------------------------------
+
+After downloading or cloning the repository, edit the `tclcheck_all.py` and change the `fc.fv`
+variable to your current firmware version. Let's assume you have a UK BBB100-2, so your PRD would
+be `PRD-63117-003` and as of September 2017, your firmware version would be `AAM481`. So change the
+line with `fc.fv` to:
+
+    fc.fv = "AAM481"
+
+Also change the `fc.mode` line to:
+
+    fc.mode = fc.MODE_OTA
+
+Now run the script. You'll get an output like this:
+
+```
+List of latest OTA (from AAM481) firmware by PRD:
+...
+PRD-63117-003 failed. (No update available.)
+PRD-63117-011: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (QWERTZ BBB100-2 (Germany))
+PRD-63117-015: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (BBB100-2 (NL, Belgium))
+PRD-63117-019: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (BBB100-2)
+PRD-63117-023: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (AZERTY BBB100-2 (Belgium))
+PRD-63117-025 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-027: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (QWERTY BBB100-2 (UAE))
+PRD-63117-028: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (BBB100-2)
+PRD-63117-029: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (BBB100-2)
+PRD-63117-034 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-036 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-037 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-041: AAM481 ⇨ AAN358 d819919187b46793abeaeff60dd6deee17baac4b (BBB100-2)
+PRD-63117-042 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-703 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-704 failed. (No data for requested CUREF/FV combination.)
+PRD-63117-717 failed. (No data for requested CUREF/FV combination.)
+...
+```
+
+As you can see, our `PRD-63117-003` variant doesn't have the update yet, but other variants have.
+
+You can use this info, to [install the update for a different variant](http://wiki.mbirth.de/know-how/hardware/blackberry-keyone/bb-keyone-ota-updates-for-different-variants.html).
+Just make sure to use a variant that has the same model number (`63117` = BBB100-2).
diff --git a/prds.txt b/prds.txt
index 3664c4e..b22f1a4 100644
--- a/prds.txt
+++ b/prds.txt
@@ -1,6 +1,6 @@
 PRD-63116-001 Unlocked BBB100-1 (USA)
 PRD-63116-003 Bell BBB100-1
-PRD-63116-005 BBB100-1
+PRD-63116-005 Rogers BBB100-1
 PRD-63116-007 BBB100-1
 PRD-63116-009 BBB100-1
 PRD-63116-010 BBB100-1
@@ -15,9 +15,9 @@ PRD-63116-033 BBB100-1
 PRD-63116-036 AT&T BBB100-1
 PRD-63117-003 BBB100-2 (UK)
 PRD-63117-011 QWERTZ BBB100-2 (Germany)
-PRD-63117-015 BBB100-2 (NL, Belgiums)
+PRD-63117-015 BBB100-2 (NL, Belgium)
 PRD-63117-019 BBB100-2
-PRD-63117-023 AZERTY BBB100-2 (Belgiums)
+PRD-63117-023 AZERTY BBB100-2 (Belgium)
 PRD-63117-025 BBB100-2
 PRD-63117-027 QWERTY BBB100-2 (UAE) https://forums.crackberry.com/showthread.php?t=1112475&p=12973537&viewfull=1#post12973537
 PRD-63117-028 BBB100-2