The IPC J-STD replaced the QQ-S-571 and other military standards. J-STD-004 (Requirements for Soldering Fluxes) uses a flux type naming convention based on the composition, activity levels based on corrosion testing, and the percentage level of halides in the formula. Types RO, RE, OR, and IN represent the majority component of the flux. For example, a no-clean ORL0 flux may contain a certain amount of rosin, but the majority of the components are organic acids. The flux residue activity levels are based on the results of corrosion test methods. A flux may be considered halide-free if it contains less than 0.05% halide by weight. Halides are an ionic compound that contain a halogen and can be used in fluxes to improve activity, however these may be corrosive.