These are part of the field intelligence gathering apparetis and are the eyes and ears of the Intelligence Branch of the Reistance. It will be a very complex system of civilian spies and informers in all aspcets of the day to day operations of an occupied area.
It is all secret, all vital to the cause. It is also the most dangerous becasue one who is caught by the enemy will most likely be tortured to extract information from and killed shortly theirafter. Or perhaps one of them or their family memnbers will be threatened with death if the operative does not turn and begin working for the enemy.
The intelligence Branch must also have in place a contengency plan to detect such an incident and to handle the fall out of such a breach of security.
Operatives for the Intelligence Branch could very well be operating in almost any capacity and level of exposure to the enemy. It will be the intelligence branch that will be seeking to establish it's eyes and ears in all areas to gather vital information for the Reisistence. It could be that enemy officers and soldiers may be eating regularly at a local dinner. That waitress at the dinner who serves them their food with a smile may seem to her fellow citizens as being just a little too friendly with the enemy may very well be those eyes and ears which I mentioned. It will also be the responsibilty of the intelligence branch to provide a certain level of security for her after the war is over. The general uninformed populous may very well seek vengency and retaliation against whom they thought was a collaberator.