diff --git a/LEGO1/lego/legoomni/src/worlds/registrationbook.cpp b/LEGO1/lego/legoomni/src/worlds/registrationbook.cpp
index c0e6d1ed..8f152f91 100644
--- a/LEGO1/lego/legoomni/src/worlds/registrationbook.cpp
+++ b/LEGO1/lego/legoomni/src/worlds/registrationbook.cpp
@@ -223,11 +223,15 @@ MxLong RegistrationBook::HandleKeyPress(SDL_Keycode p_key)
 // FUNCTION: LEGO1 0x100774a0
 MxLong RegistrationBook::HandleControl(LegoControlManagerNotificationParam& p_param)
 {
-	MxS16 unk0x28 = p_param.m_unk0x28;
+	MxS16 buttonId = p_param.m_unk0x28;
 
-	if (unk0x28 >= 1 && unk0x28 <= 28) {
+	if (buttonId >= 1 && buttonId <= 28) {
 		if (p_param.m_clickedObjectId == RegbookScript::c_Alphabet_Ctl) {
-			if (unk0x28 == 28) {
+			// buttonId:
+			// - [1, 26]: alphabet
+			// - 27: backspace
+			// - 28: go back to information center
+			if (buttonId == 28) {
 				DeleteObjects(&m_atomId, RegbookScript::c_iic006in_RunAnim, RegbookScript::c_iic008in_PlayWav);
 
 				if (GameState()->GetCurrentAct() == LegoGameState::e_act1) {
@@ -240,14 +244,15 @@ MxLong RegistrationBook::HandleControl(LegoControlManagerNotificationParam& p_pa
 				TransitionManager()->StartTransition(MxTransitionManager::e_mosaic, 50, FALSE, FALSE);
 			}
 			else {
-				if (unk0x28 > 28) {
+				if (buttonId > 28) {
 					return 1;
 				}
 
-				HandleKeyPress(unk0x28 < 27 ? unk0x28 + 64 : 8);
+				HandleKeyPress(buttonId < 27 ? SDLK_A + buttonId - 1 : SDLK_BACKSPACE);
 			}
 		}
 		else {
+			// Select another profile (buttonId is always 1)
 			InputManager()->DisableInputProcessing();
 			DeleteObjects(&m_atomId, RegbookScript::c_iic006in_RunAnim, RegbookScript::c_iic008in_PlayWav);