diff --git a/data/pc/1.21.3/protocol.json b/data/pc/1.21.3/protocol.json
index 16136d5d2..b3aa320c7 100644
--- a/data/pc/1.21.3/protocol.json
+++ b/data/pc/1.21.3/protocol.json
@@ -1591,7 +1591,7 @@
                 "container",
                 [
                   {
-                    "name": "item",
+                    "name": "itemId",
                     "type": "varint"
                   },
                   {
@@ -6066,49 +6066,19 @@
             {
               "name": "action",
               "type": [
-                "bitfield",
-                [
-                  {
-                    "name": "unused",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "update_priority",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "update_display_name",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "update_latency",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "update_listed",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "update_game_mode",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "initialize_chat",
-                    "size": 1,
-                    "signed": false
-                  },
-                  {
-                    "name": "add_player",
-                    "size": 1,
-                    "signed": false
-                  }
-                ]
+                "bitflags",
+                {
+                  "type": "u8",
+                  "flags": [
+                    "add_player",
+                    "initialize_chat",
+                    "update_game_mode",
+                    "update_listed",
+                    "update_latency",
+                    "update_display_name",
+                    "update_priority"
+                  ]
+                }
               ]
             },
             {
@@ -6131,7 +6101,7 @@
                           {
                             "compareTo": "../action/add_player",
                             "fields": {
-                              "1": "game_profile"
+                              "true": "game_profile"
                             },
                             "default": "void"
                           }
@@ -6144,7 +6114,7 @@
                           {
                             "compareTo": "../action/initialize_chat",
                             "fields": {
-                              "1": "chat_session"
+                              "true": "chat_session"
                             },
                             "default": "void"
                           }
@@ -6157,7 +6127,7 @@
                           {
                             "compareTo": "../action/update_game_mode",
                             "fields": {
-                              "1": "varint"
+                              "true": "varint"
                             },
                             "default": "void"
                           }
@@ -6170,7 +6140,7 @@
                           {
                             "compareTo": "../action/update_listed",
                             "fields": {
-                              "1": "varint"
+                              "true": "varint"
                             },
                             "default": "void"
                           }
@@ -6183,7 +6153,7 @@
                           {
                             "compareTo": "../action/update_latency",
                             "fields": {
-                              "1": "varint"
+                              "true": "varint"
                             },
                             "default": "void"
                           }
@@ -6196,7 +6166,7 @@
                           {
                             "compareTo": "../action/update_display_name",
                             "fields": {
-                              "1": [
+                              "true": [
                                 "option",
                                 "anonymousNbt"
                               ]
@@ -6212,7 +6182,7 @@
                           {
                             "compareTo": "../action/update_priority",
                             "fields": {
-                              "1": "varint"
+                              "true": "varint"
                             },
                             "default": "void"
                           }
diff --git a/data/pc/latest/proto.yml b/data/pc/latest/proto.yml
index 97ce1f45d..90b318c1e 100644
--- a/data/pc/latest/proto.yml
+++ b/data/pc/latest/proto.yml
@@ -562,7 +562,7 @@
       _: itemCount ?
          if 0: void
          default:
-            item: varint
+            itemId: varint
 # https://wiki.vg/Slot_Data#Structured_components
             addedComponentCount: varint
             removedComponentCount: varint
@@ -2099,39 +2099,40 @@
       players: UUID[]varint
    # MC: ClientboundPlayerInfoUpdatePacket
    packet_player_info:
-      # action is a bitfield of the above
-      action: ["bitfield", [
-         { "name": "unused", "size": 1, "signed": false },
-         { "name": "update_priority", "size": 1, "signed": false },
-         { "name": "update_display_name", "size": 1, "signed": false },
-         { "name": "update_latency", "size": 1, "signed": false },
-         { "name": "update_listed", "size": 1, "signed": false },
-         { "name": "update_game_mode", "size": 1, "signed": false },
-         { "name": "initialize_chat", "size": 1, "signed": false },
-         { "name": "add_player", "size": 1, "signed": false }
-      ]]
+      action: ["bitflags", {
+         "type": "u8",
+         "flags": [
+            "add_player",
+            "initialize_chat",
+            "update_game_mode",
+            "update_listed",
+            "update_latency",
+            "update_display_name",
+            "update_priority"
+         ]
+      }]
       data: []varint
          uuid: UUID
          player: ../action/add_player ?
-            if 1: game_profile
+            if true: game_profile
             default: void
          chatSession: ../action/initialize_chat ?
-            if 1: chat_session
+            if true: chat_session
             default: void
          gamemode: ../action/update_game_mode ?
-            if 1: varint
+            if true: varint
             default: void
          listed: ../action/update_listed ?
-            if 1: varint
+            if true: varint
             default: void
          latency: ../action/update_latency ?
-            if 1: varint
+            if true: varint
             default: void
          displayName: ../action/update_display_name ?
-            if 1: ["option", "anonymousNbt"]
+            if true: ["option", "anonymousNbt"]
             default: void
          listPriority: ../action/update_priority ?
-            if 1: varint
+            if true: varint
             default: void
 
    # MC: ClientboundPlayerLookAtPacket