diff --git a/CMakeLists.txt b/CMakeLists.txt
index ec48b544..6a0a55d9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,7 @@ set(SOURCES
     src/CatSession.cc
     src/Channel.cc
     src/ChatCommands.cc
+    src/ChoiceSearch.cc
     src/Client.cc
     src/CommonItemSet.cc
     src/Compression.cc
diff --git a/TODO.md b/TODO.md
index 1f8afbd4..76ed0113 100644
--- a/TODO.md
+++ b/TODO.md
@@ -2,7 +2,6 @@
 
 - Find a way to silence audio in RunDOL.s
 - Encapsulate BB server-side random state and make replays deterministic
-- Implement choice search
 - Write a simple status API
 - Implement per-game logging
 - Build an exception-handling abstraction in ChatCommands that shows formatted error messages in all cases
diff --git a/src/ChatCommands.cc b/src/ChatCommands.cc
index f5495126..3812910e 100644
--- a/src/ChatCommands.cc
+++ b/src/ChatCommands.cc
@@ -112,7 +112,7 @@ static void server_command_lobby_info(shared_ptr<Client> c, const std::string&)
         } else {
           lines.emplace_back(string_printf("$C6%08X$C7 L$C6%d-%d$C7", l->lobby_id, l->min_level + 1, l->max_level + 1));
         }
-        lines.emplace_back(string_printf("$C7Section ID: $C6%s$C7", name_for_section_id(l->section_id).c_str()));
+        lines.emplace_back(string_printf("$C7Section ID: $C6%s$C7", name_for_section_id(l->section_id)));
 
         if (l->check_flag(Lobby::Flag::DROPS_ENABLED)) {
           if (l->item_creator) {
@@ -751,8 +751,7 @@ static void server_command_secid(shared_ptr<Client> c, const std::string& args)
       send_text_message(c, "$C6Invalid section ID");
     } else {
       c->config.override_section_id = new_secid;
-      string name = name_for_section_id(new_secid);
-      send_text_message_printf(c, "$C6Override section ID\nset to %s", name.c_str());
+      send_text_message_printf(c, "$C6Override section ID\nset to %s", name_for_section_id(new_secid));
     }
   }
 }
@@ -768,8 +767,7 @@ static void proxy_command_secid(shared_ptr<ProxyServer::LinkedSession> ses, cons
       send_text_message(ses->client_channel, "$C6Invalid section ID");
     } else {
       ses->config.override_section_id = new_secid;
-      string name = name_for_section_id(new_secid);
-      send_text_message(ses->client_channel, "$C6Override section ID\nset to " + name);
+      send_text_message_printf(ses->client_channel, "$C6Override section ID\nset to %s", name_for_section_id(new_secid));
     }
   }
 }
diff --git a/src/ChoiceSearch.cc b/src/ChoiceSearch.cc
new file mode 100644
index 00000000..c69728c1
--- /dev/null
+++ b/src/ChoiceSearch.cc
@@ -0,0 +1,149 @@
+#include "ChoiceSearch.hh"
+
+#include <inttypes.h>
+#include <string.h>
+
+#include "Client.hh"
+
+using namespace std;
+
+const vector<ChoiceSearchCategory> CHOICE_SEARCH_CATEGORIES({
+    ChoiceSearchCategory{
+        .id = 0x0001,
+        .name = "Level",
+        .choices = {
+            {0x0000, "Any"},
+            {0x0001, "Own level +/- 5"},
+            {0x0002, "Level 1-10"},
+            {0x0003, "Level 11-20"},
+            {0x0004, "Level 21-40"},
+            {0x0005, "Level 41-60"},
+            {0x0006, "Level 61-80"},
+            {0x0007, "Level 81-100"},
+            {0x0008, "Level 101-120"},
+            {0x0009, "Level 121-160"},
+            {0x000A, "Level 161-200"},
+        },
+        .client_matches = +[](shared_ptr<Client> searcher_c, shared_ptr<Client> target_c, uint16_t choice_id) -> bool {
+          if (choice_id == 0x0000) {
+            return true;
+          }
+          uint32_t target_level = target_c->game_data.character()->disp.stats.level + 1;
+          switch (choice_id) {
+            case 0x0001:
+              return (labs(static_cast<int32_t>(target_level - searcher_c->game_data.character()->disp.stats.level)) <= 5);
+            case 0x0002:
+              return (target_level <= 10);
+            case 0x0003:
+              return (target_level > 10) && (target_level <= 20);
+            case 0x0004:
+              return (target_level > 20) && (target_level <= 40);
+            case 0x0005:
+              return (target_level > 40) && (target_level <= 60);
+            case 0x0006:
+              return (target_level > 60) && (target_level <= 80);
+            case 0x0007:
+              return (target_level > 80) && (target_level <= 100);
+            case 0x0008:
+              return (target_level > 100) && (target_level <= 120);
+            case 0x0009:
+              return (target_level > 120) && (target_level <= 160);
+            case 0x000A:
+              return (target_level > 160) && (target_level <= 200);
+          }
+          return false;
+        },
+    },
+    ChoiceSearchCategory{
+        .id = 0x0002,
+        .name = "Class",
+        .choices = {
+            {0x0000, "Any"},
+            {0x0010, "Hunter"},
+            {0x0001, "HUmar"},
+            {0x0002, "HUnewearl"},
+            {0x0003, "HUcast"},
+            {0x000A, "HUcaseal"},
+            {0x0011, "Ranger"},
+            {0x0004, "RAmar"},
+            {0x000C, "RAmarl"},
+            {0x0005, "RAcast"},
+            {0x0006, "RAcaseal"},
+            {0x0012, "Force"},
+            {0x000B, "FOmar"},
+            {0x0007, "FOmarl"},
+            {0x0008, "FOnewm"},
+            {0x0009, "FOnewearl"},
+        },
+        .client_matches = +[](shared_ptr<Client>, shared_ptr<Client> target_c, uint16_t choice_id) -> bool {
+          switch (choice_id) {
+            case 0x0000:
+              return true;
+            case 0x0010:
+              return target_c->game_data.character()->disp.visual.class_flags & 0x20;
+            case 0x0011:
+              return target_c->game_data.character()->disp.visual.class_flags & 0x40;
+            case 0x0012:
+              return target_c->game_data.character()->disp.visual.class_flags & 0x80;
+            default:
+              return ((choice_id - 1) == target_c->game_data.character()->disp.visual.char_class);
+          }
+        },
+    },
+    ChoiceSearchCategory{
+        .id = 0x0003,
+        .name = "Platform",
+        .choices = {
+            {0x0000, "Any"},
+            {0x0001, "DC betas"},
+            {0x0002, "DC V1"},
+            {0x0003, "DC V2 / PC"},
+            {0x0004, "GC / Xbox Episodes 1&2"},
+            {0x0005, "GC Episode 3"},
+            {0x0006, "BB"},
+        },
+        .client_matches = +[](shared_ptr<Client>, shared_ptr<Client> target_c, uint16_t choice_id) -> bool {
+          if (choice_id == 0x0000) {
+            return true;
+          }
+          switch (target_c->version()) {
+            case Version::DC_NTE:
+            case Version::DC_V1_11_2000_PROTOTYPE:
+              return (choice_id == 0x0001);
+            case Version::DC_V1:
+              return (choice_id == 0x0002);
+            case Version::DC_V2:
+            case Version::PC_V2:
+              return (choice_id == 0x0003);
+            case Version::GC_NTE:
+            case Version::GC_V3:
+            case Version::XB_V3:
+              return (choice_id == 0x0004);
+            case Version::GC_EP3_TRIAL_EDITION:
+            case Version::GC_EP3:
+              return (choice_id == 0x0005);
+            case Version::BB_V4:
+              return (choice_id == 0x0006);
+            default:
+              return false;
+          }
+        },
+    },
+    ChoiceSearchCategory{
+        .id = 0x0204,
+        .name = "Game mode",
+        .choices = {
+            {0x0000, "Any"},
+            {0x0001, "Normal"},
+            {0x0002, "Hard"},
+            {0x0003, "Very Hard"},
+            {0x0004, "Ultimate"},
+            {0x0005, "Battle"},
+            {0x0006, "Challenge"},
+        },
+        .client_matches = +[](shared_ptr<Client>, shared_ptr<Client> target_c, uint16_t choice_id) -> bool {
+          uint16_t target_choice_id = target_c->game_data.character()->choice_search_config.get_setting(0x0204);
+          return (choice_id == 0) || (target_choice_id == 0) || (choice_id == target_choice_id);
+        },
+    },
+});
diff --git a/src/ChoiceSearch.hh b/src/ChoiceSearch.hh
new file mode 100644
index 00000000..e6a390b8
--- /dev/null
+++ b/src/ChoiceSearch.hh
@@ -0,0 +1,43 @@
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <phosg/Encoding.hh>
+#include <string>
+#include <vector>
+
+#include "Text.hh"
+
+struct Client;
+
+struct ChoiceSearchConfig {
+  le_uint32_t disabled = 1; // 0 = enabled, 1 = disabled. Unused in command C3
+  struct Entry {
+    le_uint16_t parent_choice_id = 0;
+    le_uint16_t choice_id = 0;
+  } __attribute__((packed));
+  parray<Entry, 5> entries;
+
+  int32_t get_setting(uint16_t parent_choice_id) const {
+    for (size_t z = 0; z < this->entries.size(); z++) {
+      if (this->entries[z].parent_choice_id == parent_choice_id) {
+        return this->entries[z].choice_id;
+      }
+    }
+    return -1;
+  }
+} __attribute__((packed));
+
+struct ChoiceSearchCategory {
+  struct Choice {
+    uint16_t id;
+    const char* name;
+  };
+
+  uint16_t id;
+  const char* name;
+  std::vector<Choice> choices;
+  std::function<bool(std::shared_ptr<Client> searcher_c, std::shared_ptr<Client> target_c, uint16_t choice_id)> client_matches;
+};
+
+extern const std::vector<ChoiceSearchCategory> CHOICE_SEARCH_CATEGORIES;
diff --git a/src/CommandFormats.hh b/src/CommandFormats.hh
index 8f6e1207..a917b1cf 100644
--- a/src/CommandFormats.hh
+++ b/src/CommandFormats.hh
@@ -605,9 +605,10 @@ struct SC_MeetUserExtension {
     le_uint32_t menu_id = 0;
     le_uint32_t item_id = 0;
   } __packed__;
-  parray<LobbyReference, 8> lobby_refs;
-  le_uint32_t unknown_a2 = 0;
-  pstring<Encoding, 0x20> player_name;
+  /* 00 */ parray<LobbyReference, 8> lobby_refs;
+  /* 40 */ le_uint32_t unknown_a2 = 0;
+  /* 44 */ pstring<Encoding, 0x20> player_name;
+  /* 64 (or 84 on UTF16 versions) */
 } __packed__;
 
 struct S_LegacyJoinGame_PC_0E {
@@ -1103,7 +1104,7 @@ struct C_CharacterData_DCv2_61_98 {
   /* 0000 */ PlayerInventory inventory;
   /* 034C */ PlayerDispDataDCPCV3 disp;
   /* 041C */ PlayerRecordsEntry_DC records;
-  /* 04D8 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 04D8 */ ChoiceSearchConfig choice_search_config;
   /* 04F0 */
 } __attribute__((packed));
 
@@ -1111,7 +1112,7 @@ struct C_CharacterData_PC_61_98 {
   /* 0000 */ PlayerInventory inventory;
   /* 034C */ PlayerDispDataDCPCV3 disp;
   /* 041C */ PlayerRecordsEntry_PC records;
-  /* 0510 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 0510 */ ChoiceSearchConfig choice_search_config;
   /* 0528 */ parray<le_uint32_t, 0x1E> blocked_senders;
   /* 05A0 */ le_uint32_t auto_reply_enabled = 0;
   // The auto-reply message can be up to 0x200 characters. If it's shorter than
@@ -1124,7 +1125,7 @@ struct C_CharacterData_V3_61_98 {
   /* 0000 */ PlayerInventory inventory;
   /* 034C */ PlayerDispDataDCPCV3 disp;
   /* 041C */ PlayerRecordsEntry_V3 records;
-  /* 0538 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 0538 */ ChoiceSearchConfig choice_search_config;
   /* 0550 */ pstring<TextEncoding::MARKED, 0xAC> info_board;
   /* 05FC */ parray<le_uint32_t, 0x1E> blocked_senders;
   /* 0674 */ le_uint32_t auto_reply_enabled = 0;
@@ -1138,7 +1139,7 @@ struct C_CharacterData_GC_Ep3_61_98 {
   /* 0000 */ PlayerInventory inventory;
   /* 034C */ PlayerDispDataDCPCV3 disp;
   /* 041C */ PlayerRecordsEntry_V3 records;
-  /* 0538 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 0538 */ ChoiceSearchConfig choice_search_config;
   /* 0550 */ pstring<TextEncoding::MARKED, 0xAC> info_board;
   /* 05FC */ parray<le_uint32_t, 0x1E> blocked_senders;
   /* 0674 */ le_uint32_t auto_reply_enabled = 0;
@@ -1151,7 +1152,7 @@ struct C_CharacterData_BB_61_98 {
   /* 0000 */ PlayerInventory inventory;
   /* 034C */ PlayerDispDataBB disp;
   /* 04DC */ PlayerRecordsEntry_BB records;
-  /* 0638 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 0638 */ ChoiceSearchConfig choice_search_config;
   /* 0650 */ pstring<TextEncoding::UTF16, 0xAC> info_board;
   /* 07A8 */ parray<le_uint32_t, 0x1E> blocked_senders;
   /* 0820 */ le_uint32_t auto_reply_enabled = 0;
@@ -2359,19 +2360,17 @@ struct S_TournamentMatchInformation_GC_Ep3_BB {
 // Internal name: RcvChoiceList
 
 // Command is a list of these; header.flag is the entry count (incl. top-level).
-template <typename ItemIDT, TextEncoding Encoding>
+template <TextEncoding Encoding>
 struct S_ChoiceSearchEntry {
   // Category IDs are nonzero; if the high byte of the ID is nonzero then the
   // category can be set by the user at any time; otherwise it can't.
-  ItemIDT parent_category_id = 0; // 0 for top-level categories
-  ItemIDT category_id = 0;
+  le_uint16_t parent_choice_id = 0; // 0 for top-level categories
+  le_uint16_t choice_id = 0;
   pstring<Encoding, 0x1C> text;
 } __packed__;
-struct S_ChoiceSearchEntry_DC_C0 : S_ChoiceSearchEntry<le_uint32_t, TextEncoding::MARKED> {
+struct S_ChoiceSearchEntry_DC_V3_C0 : S_ChoiceSearchEntry<TextEncoding::MARKED> {
 } __packed__;
-struct S_ChoiceSearchEntry_V3_C0 : S_ChoiceSearchEntry<le_uint16_t, TextEncoding::MARKED> {
-} __packed__;
-struct S_ChoiceSearchEntry_PC_BB_C0 : S_ChoiceSearchEntry<le_uint16_t, TextEncoding::UTF16> {
+struct S_ChoiceSearchEntry_PC_BB_C0 : S_ChoiceSearchEntry<TextEncoding::UTF16> {
 } __packed__;
 
 // Top-level categories are things like "Level", "Class", etc.
@@ -2425,12 +2424,7 @@ struct C_CreateGame_BB_C1 : C_CreateGame<TextEncoding::UTF16> {
 // C2 (C->S): Set choice search parameters (DCv2 and later versions)
 // Internal name: PutChoiceList
 // Server does not respond.
-// The ChoiceSearchConfig structure is defined in PlayerSubordinates.hh.
-
-struct C_ChoiceSearchSelections_DC_C2_C3 : ChoiceSearchConfig<le_uint32_t> {
-} __packed__;
-struct C_ChoiceSearchSelections_PC_V3_BB_C2_C3 : ChoiceSearchConfig<le_uint16_t> {
-} __packed__;
+// Contents is a ChoiceSearchConfig, which is defined in PlayerSubordinates.hh.
 
 // C3 (C->S): Execute choice search (DCv2 and later versions)
 // Internal name: SndChoiceSeq
@@ -2441,22 +2435,25 @@ struct C_ChoiceSearchSelections_PC_V3_BB_C2_C3 : ChoiceSearchConfig<le_uint16_t>
 // Internal name: RcvChoiceAns
 
 // Command is a list of these; header.flag is the entry count
-struct S_ChoiceSearchResultEntry_V3_C4 {
+template <typename HeaderT, TextEncoding NameEncoding, TextEncoding DescEncoding, TextEncoding LocatorEncoding>
+struct S_ChoiceSearchResultEntry_C4 {
   le_uint32_t guild_card_number = 0;
-  pstring<TextEncoding::ASCII, 0x10> name; // No language marker, as usual on V3
-  pstring<TextEncoding::MARKED, 0x20> info_string; // Usually something like "<class> Lvl <level>"
+  pstring<NameEncoding, 0x10> name;
+  pstring<DescEncoding, 0x20> info_string; // Usually something like "<class> Lvl <level>"
   // Format is stricter here; this is "LOBBYNAME,BLOCKNUM,SHIPNAME"
   // If target is in game, for example, "Game Name,BLOCK01,Alexandria"
   // If target is in lobby, for example, "BLOCK01-1,BLOCK01,Alexandria"
-  pstring<TextEncoding::MARKED, 0x34> locator_string;
-  // Server IP and port for "meet user" option
-  le_uint32_t server_ip = 0;
-  le_uint16_t server_port = 0;
-  le_uint16_t unused1 = 0;
-  le_uint32_t menu_id = 0;
-  le_uint32_t lobby_id = 0; // These two are guesses
-  le_uint32_t game_id = 0; // Zero if target is in a lobby rather than a game
-  parray<uint8_t, 0x58> unused2;
+  pstring<LocatorEncoding, 0x30> location_string;
+  HeaderT reconnect_command_header; // Ignored by the client
+  S_Reconnect_19 reconnect_command;
+  SC_MeetUserExtension<NameEncoding> meet_user;
+} __packed__;
+
+struct S_ChoiceSearchResultEntry_DC_V3_C4 : S_ChoiceSearchResultEntry_C4<PSOCommandHeaderDCV3, TextEncoding::ASCII, TextEncoding::MARKED, TextEncoding::ASCII> {
+} __packed__;
+struct S_ChoiceSearchResultEntry_PC_C4 : S_ChoiceSearchResultEntry_C4<PSOCommandHeaderPC, TextEncoding::UTF16, TextEncoding::UTF16, TextEncoding::UTF16> {
+} __packed__;
+struct S_ChoiceSearchResultEntry_BB_C4 : S_ChoiceSearchResultEntry_C4<PSOCommandHeaderBB, TextEncoding::UTF16, TextEncoding::UTF16, TextEncoding::UTF16> {
 } __packed__;
 
 // C5 (S->C): Player records update (DCv2 and later versions)
diff --git a/src/IPStackSimulator.hh b/src/IPStackSimulator.hh
index 55f16a44..2456d362 100644
--- a/src/IPStackSimulator.hh
+++ b/src/IPStackSimulator.hh
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <netinet/in.h>
 #include <stdint.h>
 
diff --git a/src/PlayerSubordinates.hh b/src/PlayerSubordinates.hh
index 5905977f..22d64e37 100644
--- a/src/PlayerSubordinates.hh
+++ b/src/PlayerSubordinates.hh
@@ -10,6 +10,7 @@
 #include <utility>
 #include <vector>
 
+#include "ChoiceSearch.hh"
 #include "FileContentsCache.hh"
 #include "ItemData.hh"
 #include "LevelTable.hh"
@@ -453,17 +454,6 @@ struct PlayerRecords_Battle {
   /* 18 */
 } __attribute__((packed));
 
-template <typename ItemIDT>
-struct ChoiceSearchConfig {
-  // 0 = enabled, 1 = disabled. Unused for command C3
-  le_uint32_t disabled = 1;
-  struct Entry {
-    ItemIDT parent_category_id = 0;
-    ItemIDT category_id = 0;
-  } __attribute__((packed));
-  parray<Entry, 5> entries;
-} __attribute__((packed));
-
 template <typename DestT, typename SrcT = DestT>
 DestT convert_player_disp_data(const SrcT&, uint8_t, uint8_t) {
   static_assert(always_false<DestT, SrcT>::v,
diff --git a/src/ProxyCommands.cc b/src/ProxyCommands.cc
index 8086b2ed..edd699da 100644
--- a/src/ProxyCommands.cc
+++ b/src/ProxyCommands.cc
@@ -787,7 +787,9 @@ static HandlerResult S_C4(shared_ptr<ProxyServer::LinkedSession> ses, uint16_t,
   return modified ? HandlerResult::Type::MODIFIED : HandlerResult::Type::FORWARD;
 }
 
-constexpr on_command_t S_V3_C4 = &S_C4<S_ChoiceSearchResultEntry_V3_C4>;
+constexpr on_command_t S_DGX_C4 = &S_C4<S_ChoiceSearchResultEntry_DC_V3_C4>;
+constexpr on_command_t S_P_C4 = &S_C4<S_ChoiceSearchResultEntry_PC_C4>;
+constexpr on_command_t S_B_C4 = &S_C4<S_ChoiceSearchResultEntry_BB_C4>;
 
 static HandlerResult S_G_E4(shared_ptr<ProxyServer::LinkedSession> ses, uint16_t, uint32_t, string& data) {
   auto& cmd = check_size_t<S_CardBattleTableState_GC_Ep3_E4>(data);
@@ -1962,8 +1964,8 @@ static on_command_t handlers[0x100][13][2] = {
 /* C1 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
 /* C2 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
 /* C3 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
-/* C4 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {nullptr,          nullptr},     {nullptr,          nullptr},     {nullptr,          nullptr},      {nullptr,       nullptr},      {nullptr,          nullptr},     {S_V3_C4,          nullptr},      {S_V3_C4,          nullptr},      {S_V3_C4,          nullptr},      {S_V3_C4,       nullptr},      {nullptr,      nullptr}},
-/* C5 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {nullptr,          nullptr},     {nullptr,          nullptr},     {nullptr,          nullptr},      {nullptr,       nullptr},      {nullptr,          nullptr},     {nullptr,          nullptr},      {nullptr,          nullptr},      {nullptr,          nullptr},      {nullptr,       nullptr},      {nullptr,      nullptr}},
+/* C4 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_DGX_C4,         nullptr},      {S_P_C4,        nullptr},      {S_DGX_C4,         nullptr},     {S_DGX_C4,         nullptr},      {S_DGX_C4,         nullptr},      {S_DGX_C4,         nullptr},      {S_DGX_C4,      nullptr},      {S_B_C4,       nullptr}},
+/* C5 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {nullptr,          nullptr},      {nullptr,       nullptr},      {nullptr,          nullptr},     {nullptr,          nullptr},      {nullptr,          nullptr},      {nullptr,          nullptr},      {nullptr,       nullptr},      {nullptr,      nullptr}},
 /* C6 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
 /* C7 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
 /* C8 */ {{S_invalid,     nullptr}, {S_invalid,     nullptr}, {nullptr, nullptr}, {S_invalid,        nullptr},     {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,        nullptr},     {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,        nullptr},      {S_invalid,     nullptr},      {S_invalid,    nullptr}},
diff --git a/src/QuestScript.cc b/src/QuestScript.cc
index 419d6b3d..eef1a577 100644
--- a/src/QuestScript.cc
+++ b/src/QuestScript.cc
@@ -1412,8 +1412,7 @@ std::string disassemble_quest_script(const void* data, size_t size, Version vers
       string unused = format_data_string(visual.unused.data(), visual.unused.bytes());
       lines.emplace_back(string_printf("  %04zX  unused               %s", l->offset + offsetof(PlayerVisualConfig, unused), unused.c_str()));
       lines.emplace_back(string_printf("  %04zX  name_color_checksum  %08" PRIX32, l->offset + offsetof(PlayerVisualConfig, name_color_checksum), visual.name_color_checksum.load()));
-      string secid_name = name_for_section_id(visual.section_id);
-      lines.emplace_back(string_printf("  %04zX  section_id           %02hhX (%s)", l->offset + offsetof(PlayerVisualConfig, section_id), visual.section_id, secid_name.c_str()));
+      lines.emplace_back(string_printf("  %04zX  section_id           %02hhX (%s)", l->offset + offsetof(PlayerVisualConfig, section_id), visual.section_id, name_for_section_id(visual.section_id)));
       lines.emplace_back(string_printf("  %04zX  char_class           %02hhX (%s)", l->offset + offsetof(PlayerVisualConfig, char_class), visual.char_class, name_for_char_class(visual.char_class)));
       lines.emplace_back(string_printf("  %04zX  validation_flags     %02hhX", l->offset + offsetof(PlayerVisualConfig, validation_flags), visual.validation_flags));
       lines.emplace_back(string_printf("  %04zX  version              %02hhX", l->offset + offsetof(PlayerVisualConfig, version), visual.version));
diff --git a/src/RareItemSet.cc b/src/RareItemSet.cc
index 60b67d2e..ca73476d 100644
--- a/src/RareItemSet.cc
+++ b/src/RareItemSet.cc
@@ -518,12 +518,11 @@ void RareItemSet::print_collection(
     return;
   }
 
-  string secid_name = name_for_section_id(section_id);
   fprintf(stream, "%s %s %s %s\n",
       name_for_mode(mode),
       name_for_episode(episode),
       name_for_difficulty(difficulty),
-      secid_name.c_str());
+      name_for_section_id(section_id));
 
   fprintf(stream, "  Monster rares:\n");
   for (size_t z = 0; z < collection->rt_index_to_specs.size(); z++) {
diff --git a/src/ReceiveCommands.cc b/src/ReceiveCommands.cc
index ecf9032a..b5438d8b 100644
--- a/src/ReceiveCommands.cc
+++ b/src/ReceiveCommands.cc
@@ -1720,12 +1720,11 @@ static void on_09(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
           }
         }
 
-        string secid_str = name_for_section_id(game->section_id);
         info += string_printf("%s %c %s %s\n",
             abbreviation_for_episode(game->episode),
             abbreviation_for_difficulty(game->difficulty),
             abbreviation_for_mode(game->mode),
-            secid_str.c_str());
+            name_for_section_id(game->section_id));
 
         bool cheats_enabled = game->check_flag(Lobby::Flag::CHEATS_ENABLED);
         bool locked = !game->password.empty();
@@ -3490,8 +3489,99 @@ static void on_40(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
 }
 
 static void on_C0(shared_ptr<Client> c, uint16_t, uint32_t, string&) {
-  // TODO: Implement choice search.
-  send_text_message(c, "$C6Choice Search is\nnot supported");
+  send_choice_search_choices(c);
+}
+
+static void on_C2(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
+  c->game_data.character()->choice_search_config = check_size_t<ChoiceSearchConfig>(data);
+}
+
+template <typename ResultT>
+static void on_choice_search_t(shared_ptr<Client> c, const ChoiceSearchConfig& cmd) {
+  auto s = c->require_server_state();
+
+  vector<ResultT> results;
+  for (const auto& l : s->all_lobbies()) {
+    for (const auto& lc : l->clients) {
+      if (!lc || lc->game_data.character()->choice_search_config.disabled) {
+        continue;
+      }
+
+      bool is_match = true;
+      for (const auto& cat : CHOICE_SEARCH_CATEGORIES) {
+        int32_t setting = cmd.get_setting(cat.id);
+        if (setting == -1) {
+          continue;
+        }
+        try {
+          if (!cat.client_matches(c, lc, setting)) {
+            is_match = false;
+            break;
+          }
+        } catch (const exception& e) {
+          c->log.info("Error in Choice Search matching for category %s: %s", cat.name, e.what());
+        }
+      }
+
+      if (is_match) {
+        auto lp = lc->game_data.character();
+        auto& result = results.emplace_back();
+        result.guild_card_number = lc->license->serial_number;
+        result.name.encode(lp->disp.name.decode(lc->language()), c->language());
+        string info_string = string_printf("%s Lv%zu %s",
+            name_for_char_class(lp->disp.visual.char_class),
+            static_cast<size_t>(lp->disp.stats.level + 1),
+            name_for_section_id(lp->disp.visual.section_id));
+        result.info_string.encode(info_string, c->language());
+        string lobby_name = l->is_game() ? l->name : string_printf("BLOCK01-%02" PRIu32, l->lobby_id);
+        string location_string;
+        if (l->is_game()) {
+          location_string = string_printf("%s,BLOCK01,%s", l->name.c_str(), s->name.c_str());
+        } else if (l->is_ep3()) {
+          location_string = string_printf("BLOCK01-C%02" PRIu32 ",BLOCK01,%s", l->lobby_id - 15, s->name.c_str());
+        } else {
+          location_string = string_printf("BLOCK01-%02" PRIu32 ",BLOCK01,%s", l->lobby_id, s->name.c_str());
+        }
+        result.location_string.encode(location_string, c->language());
+        result.reconnect_command_header.command = 0x19;
+        result.reconnect_command_header.flag = 0x00;
+        result.reconnect_command_header.size = sizeof(result.reconnect_command) + sizeof(result.reconnect_command_header);
+        result.reconnect_command.address = s->connect_address_for_client(c);
+        result.reconnect_command.port = s->name_to_port_config.at(lobby_port_name_for_version(c->version()))->port;
+        result.meet_user.lobby_refs[0].menu_id = MenuID::LOBBY;
+        result.meet_user.lobby_refs[0].item_id = l->lobby_id;
+        result.meet_user.player_name.encode(lp->disp.name.decode(lc->language()), c->language());
+        if (results.size() >= 0x20) {
+          break;
+        }
+      }
+    }
+  }
+
+  send_command_vt(c, 0xC4, results.size(), results);
+}
+
+static void on_C3(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
+  const auto& cmd = check_size_t<ChoiceSearchConfig>(data);
+  switch (c->version()) {
+      // DC V1 and the prototypes do not support this command
+    case Version::DC_V2:
+    case Version::GC_NTE:
+    case Version::GC_V3:
+    case Version::GC_EP3_TRIAL_EDITION:
+    case Version::GC_EP3:
+    case Version::XB_V3:
+      on_choice_search_t<S_ChoiceSearchResultEntry_DC_V3_C4>(c, cmd);
+      break;
+    case Version::PC_V2:
+      on_choice_search_t<S_ChoiceSearchResultEntry_PC_C4>(c, cmd);
+      break;
+    case Version::BB_V4:
+      on_choice_search_t<S_ChoiceSearchResultEntry_BB_C4>(c, cmd);
+      break;
+    default:
+      throw runtime_error("unimplemented versioned command");
+  }
 }
 
 static void on_81(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
@@ -5095,10 +5185,10 @@ static on_command_t handlers[0x100][13] = {
 /* BE */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
 /* BF */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
 //        PC_PATCH BB_PATCH DC_NTE         DC_PROTO       DCV1           DCV2            PC           GCNTE           GC              EP3TE           EP3             XB              BB
-/* C0 */ {nullptr, nullptr, on_C0,         on_C0,         on_C0,         on_C0,          on_C0,       on_C0,          on_C0,          on_C0,          on_C0,          on_C0,          nullptr},
+/* C0 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       on_C0,          on_C0,       on_C0,          on_C0,          on_C0,          on_C0,          on_C0,          on_C0},
 /* C1 */ {nullptr, nullptr, on_0C_C1_E7_EC,on_0C_C1_E7_EC,on_0C_C1_E7_EC,on_0C_C1_E7_EC, on_C1_PC,    on_0C_C1_E7_EC, on_0C_C1_E7_EC, on_0C_C1_E7_EC, on_0C_C1_E7_EC, on_0C_C1_E7_EC, on_C1_BB},
-/* C2 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
-/* C3 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
+/* C2 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       on_C2,          on_C2,       on_C2,          on_C2,          on_C2,          on_C2,          on_C2,          on_C2},
+/* C3 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       on_C3,          on_C3,       on_C3,          on_C3,          on_C3,          on_C3,          on_C3,          on_C3},
 /* C4 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
 /* C5 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        nullptr,     nullptr,        nullptr,        nullptr,        nullptr,        nullptr,        nullptr},
 /* C6 */ {nullptr, nullptr, nullptr,       nullptr,       nullptr,       nullptr,        on_C6,       on_C6,          on_C6,          on_C6,          on_C6,          on_C6,          on_C6},
diff --git a/src/ReceiveCommands.hh b/src/ReceiveCommands.hh
index 9101cbf4..8b86229e 100644
--- a/src/ReceiveCommands.hh
+++ b/src/ReceiveCommands.hh
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <memory>
 #include <string>
 
diff --git a/src/ReceiveSubcommands.hh b/src/ReceiveSubcommands.hh
index 4beee02d..12859648 100644
--- a/src/ReceiveSubcommands.hh
+++ b/src/ReceiveSubcommands.hh
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <stdint.h>
 
 #include "Client.hh"
diff --git a/src/SaveFileFormats.hh b/src/SaveFileFormats.hh
index ac233d11..2d4454c6 100644
--- a/src/SaveFileFormats.hh
+++ b/src/SaveFileFormats.hh
@@ -10,6 +10,7 @@
 #include <phosg/Strings.hh>
 #include <string>
 
+#include "ChoiceSearch.hh"
 #include "Episode3/DataIndexes.hh"
 #include "ItemNameIndex.hh"
 #include "PSOEncryption.hh"
@@ -207,7 +208,7 @@ struct PSOBBCharacterFile {
   /* 2CB4 */ parray<uint8_t, 4> unknown_a4;
   /* 2CB8 */ PlayerRecordsBB_Challenge challenge_records;
   /* 2DF8 */ parray<le_uint16_t, 0x0014> tech_menu_config;
-  /* 2E20 */ ChoiceSearchConfig<le_uint16_t> choice_search_config;
+  /* 2E20 */ ChoiceSearchConfig choice_search_config;
   /* 2E38 */ parray<uint8_t, 0x0010> unknown_a6;
   /* 2E48 */ parray<le_uint32_t, 0x0010> quest_global_flags;
   /* 2E88 */ parray<uint8_t, 0x1C> unknown_a7;
diff --git a/src/SendCommands.cc b/src/SendCommands.cc
index adc43a65..803be72b 100644
--- a/src/SendCommands.cc
+++ b/src/SendCommands.cc
@@ -987,6 +987,44 @@ void send_info_board(shared_ptr<Client> c) {
   }
 }
 
+template <typename CmdT>
+void send_choice_search_choices_t(shared_ptr<Client> c) {
+  vector<CmdT> entries;
+  for (const auto& cat : CHOICE_SEARCH_CATEGORIES) {
+    auto& cat_e = entries.emplace_back();
+    cat_e.parent_choice_id = 0;
+    cat_e.choice_id = cat.id;
+    cat_e.text.encode(cat.name, c->language());
+    for (const auto& choice : cat.choices) {
+      auto& e = entries.emplace_back();
+      e.parent_choice_id = cat.id;
+      e.choice_id = choice.id;
+      e.text.encode(choice.name, c->language());
+    }
+  }
+  send_command_vt(c, 0xC0, entries.size(), entries);
+}
+
+void send_choice_search_choices(shared_ptr<Client> c) {
+  switch (c->version()) {
+      // DC V1 and the prototypes do not support this command
+    case Version::DC_V2:
+    case Version::GC_NTE:
+    case Version::GC_V3:
+    case Version::GC_EP3_TRIAL_EDITION:
+    case Version::GC_EP3:
+    case Version::XB_V3:
+      send_choice_search_choices_t<S_ChoiceSearchEntry_DC_V3_C0>(c);
+      break;
+    case Version::PC_V2:
+    case Version::BB_V4:
+      send_choice_search_choices_t<S_ChoiceSearchEntry_PC_BB_C0>(c);
+      break;
+    default:
+      throw logic_error("unimplemented versioned command");
+  }
+}
+
 template <typename CommandHeaderT, TextEncoding Encoding>
 void send_card_search_result_t(
     shared_ptr<Client> c,
@@ -2981,7 +3019,8 @@ void send_quest_file_chunk(
   }
   cmd.data_size = size;
 
-  send_command_t(c, is_download_quest ? 0xA7 : 0x13, chunk_index, cmd);
+  c->log.info("Sending quest file chunk %s:%zu", filename.c_str(), chunk_index);
+  c->channel.send(is_download_quest ? 0xA7 : 0x13, chunk_index, &cmd, sizeof(cmd), true);
 }
 
 template <typename CommandT>
diff --git a/src/SendCommands.hh b/src/SendCommands.hh
index ca46752e..2f26d5c8 100644
--- a/src/SendCommands.hh
+++ b/src/SendCommands.hh
@@ -232,6 +232,8 @@ __attribute__((format(printf, 2, 3))) void send_ep3_text_message_printf(
 
 void send_info_board(std::shared_ptr<Client> c);
 
+void send_choice_search_choices(std::shared_ptr<Client> c);
+
 void send_card_search_result(
     std::shared_ptr<Client> c,
     std::shared_ptr<Client> result,
diff --git a/src/ServerShell.cc b/src/ServerShell.cc
index 78ca0f05..5e6d3a53 100644
--- a/src/ServerShell.cc
+++ b/src/ServerShell.cc
@@ -656,11 +656,11 @@ Proxy session commands:\n\
     for (size_t z = 0; z < ses->lobby_players.size(); z++) {
       const auto& player = ses->lobby_players[z];
       if (player.guild_card_number) {
-        auto secid_name = name_for_section_id(player.section_id);
         fprintf(stderr, "  %zu: %" PRIu32 " => %s (%c, %s, %s)\n",
             z, player.guild_card_number, player.name.c_str(),
             char_for_language_code(player.language),
-            name_for_char_class(player.char_class), secid_name.c_str());
+            name_for_char_class(player.char_class),
+            name_for_section_id(player.section_id));
       } else {
         fprintf(stderr, "  %zu: (no player)\n", z);
       }
diff --git a/src/StaticGameData.cc b/src/StaticGameData.cc
index 67f4c36c..b41f9ee9 100644
--- a/src/StaticGameData.cc
+++ b/src/StaticGameData.cc
@@ -89,7 +89,7 @@ const char* abbreviation_for_mode(GameMode mode) {
   }
 }
 
-const vector<string> section_id_to_name = {
+static const array<const char*, 10> section_id_to_name = {
     "Viridia", "Greennill", "Skyly", "Bluefull", "Purplenum",
     "Pinkal", "Redria", "Oran", "Yellowboze", "Whitill"};
 
@@ -205,12 +205,11 @@ const vector<string> npc_id_to_name({"ninja", "rico", "sonic", "knuckles", "tail
 const unordered_map<string, uint8_t> name_to_npc_id = {
     {"ninja", 0}, {"rico", 1}, {"sonic", 2}, {"knuckles", 3}, {"tails", 4}, {"flowen", 5}, {"elly", 6}};
 
-const string& name_for_section_id(uint8_t section_id) {
+const char* name_for_section_id(uint8_t section_id) {
   if (section_id < section_id_to_name.size()) {
     return section_id_to_name[section_id];
   } else {
-    static const string ret = "<Unknown section id>";
-    return ret;
+    return "<Unknown>";
   }
 }
 
diff --git a/src/StaticGameData.hh b/src/StaticGameData.hh
index fa6e2c00..b3ddf1c7 100644
--- a/src/StaticGameData.hh
+++ b/src/StaticGameData.hh
@@ -39,7 +39,7 @@ extern const std::unordered_map<std::string, uint8_t> name_to_tech_id;
 const std::string& name_for_technique(uint8_t tech);
 uint8_t technique_for_name(const std::string& name);
 
-const std::string& name_for_section_id(uint8_t section_id);
+const char* name_for_section_id(uint8_t section_id);
 uint8_t section_id_for_name(const std::string& name);
 
 const std::string& name_for_event(uint8_t event);