Hans
Your company FTLS will be published in your Ops Manual. I guess Part A section 7. It is your responsibility to know it's limitations if you work as Aircrew. If you are licensed, it is quite simple, the guys on the ground have nothing to loose, you have. It is no use at all pleading 'ignorance' after the fact. If next time it goes into one of the many grey areas, discuss with Crewing and be sure in your own mind the duty is legal.
Bored