Issue Priority Definitions - google/tie GitHub Wiki
P0 - Critical to App Function (App will not function properly without it)
P1 - Critical to User Experience (Significantly degraded experience without it)
P2 - Improvements to Function or Experience (but not critical)
P3 - Nice to haves, if we have time and aren't working on P0-P2
P4 - Tracking purposes, no action (used very rarely, if at all)