Blackline 3 : Refers to fuels that have burned, either intentionally or not. Many prescribed fire and wildfire suppression techniques are based on the concept of blackline as a barrier to fire spread
Sequoia and Kings Canyon National Parks, National Park Service, Glossary of Fire Terms, Three Rivers, California, USA 2004. http://npshistory.com/publications/nps-glossary.pd f, (For Fr - Amer) {462}