Part 5 : P2000

To recieve P2000 messages (FLEX) you need multimon-ng.
multimon-ng a fork of multimon. It decodes the following digital transmission modes:
POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE CW
First install multimon-ng

# Install dependencies
sudo apt-get update
sudo apt-get -y install git cmake build-essential libusb-1.0 qt4-qmake libpulse-dev libx11-dev
git clone https://github.com/EliasOenal/multimon-ng.git
cd multimon-ng
mkdir build
cd build
qmake ../multimon-ng.pro
make
sudo make install

Then run

rtl_fm -f 169.65M -M fm -s 22050 -l 250 | multimon-ng -a FLEX -a SCOPE -t raw /dev/stdin