Complex sentence: To maintain operational security the RFSU's are necessarily secretive about certain aspects of their work, particularly with regard to the deployment of patrols, and specific details of the techniques they use to remain undetected whilst carrying out their tasks.
Split into simpler sentences: To maintain operational security the RFSU's are necessarily secretive about certain aspects of their work, particularly with regard to the deployment of patrols. They also remain non-specific regarding details of the techniques they use to remain undetected whilst carrying out their tasks.