International French Adjectival System (IFAS)
|Straightforward, possibly a glacial approach, snow and ice will often be at an easy angle.
|Routes may be longer at altitude, with snow and ice slopes up to 45 degrees. Glaciers are more complex, scrambling is harder, climbing may require some belaying, descent may involve rappelling. More objective hazards.
|Fairly hard, snow and ice at an angle of 45-65 degrees, rock climbing up to UIAA grade III, but not sustained, belayed climbing in addition to a large amount of exposed but easier terrain. Significant objective hazard.
|Hard, more serious with rock climbing at IV and V, snow and ice slopes at 50-70 degrees. Routes may be long and sustained or harder but shorter. Serious objective hazards.
|Very hard, routes at this grades are serious undertakings with high level of objective danger. Sustained snow and ice at an angle of 65-80 degrees, rock climbing at grade V and VI with possible aid, very long sections of hard climbing.
|Extremely hard, exceptional objective danger, vertical ice slopes and rock climbing up to VI to VIII, with possible aid pitches.