What type of line allows firing without additional coordination with the establishing HQ?

A Free Fire Area (FFA) is designated when an area has been approved for the use of fire support without needing additional coordination with the higher headquarters. In an FFA, commanders can engage targets within the specified area freely, allowing for rapid response to threats and increased operational flexibility. The establishment of an FFA means that all units involved have pre-approved authority to fire upon any target within that area, streamlining the engagement process and reducing the time it takes to respond to targets, which is particularly critical in high-tempo combat situations.

In contrast, the other options are designed to manage and restrict the use of fire support to avoid collateral damage or ensure coordinated effects among various fire support elements. Coordinated Fire Lines (CFL) and Restrictive Fire Lines (RFL) both require coordination before engagement, while the Fire Support Coordination Line (FSCL) is meant to manage and direct the use of fire support to ensure effectiveness and safety during operations.