Partner has opened 1♥ or 1♠ and you hold 4+ cards in that suit. Make the appropriate raise:

• Add shortage points to your HCP: void +5, singleton +3, doubleton +1 (non-trump suits only)
• Under 6 total points → Pass
• 6–9 total points → simple raise to 2 of partner's suit
• 10–12 total points → limit raise to 3 of partner's suit (use STOP)
• 13+ total points → bid game — 4 of partner's suit (use STOP)