diff --git a/CustomStackSize/data-final-fixes.lua b/CustomStackSize/data-final-fixes.lua
index 29922c7..0e32a66 100644
--- a/CustomStackSize/data-final-fixes.lua
+++ b/CustomStackSize/data-final-fixes.lua
@@ -31,3 +31,32 @@ for _, category in pairs(stack_list) do
     end
   end
 end
+
+-- LUA doesn't have a built-in way to split strings, so...
+-- Source - https://stackoverflow.com/a/7615129
+-- Posted by user973713, modified by community. See post 'Timeline' for change history
+-- Retrieved 2026-08-20, License - CC BY-SA 4.0
+function strsplit(inputstr, sep)
+  if sep == nil then
+    sep = "%s"
+  end
+  local t = {}
+  for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
+    table.insert(t, str)
+  end
+  return t
+end
+
+-- Custom user-added rules
+for _, token in pairs(strsplit(settings.startup["stack-size-custom-others"].value, ";")) do
+  local proto_name, ssize = table.unpack(strsplit(token, "="))
+  if ssize then
+    local size = tonumber(ssize)
+    if size >= 1 and size <= 100000 then
+      local proto = find_proto(proto_name)
+      if proto then
+        proto.stack_size = size
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/CustomStackSize/locale/en/settings.cfg b/CustomStackSize/locale/en/settings.cfg
index 405aa43..5793a60 100644
--- a/CustomStackSize/locale/en/settings.cfg
+++ b/CustomStackSize/locale/en/settings.cfg
@@ -84,6 +84,7 @@ stack-size-metallic-asteroid-chunk=Space → Metallic asteroid chunk
 stack-size-carbonic-asteroid-chunk=Space → Carbonic asteroid chunk
 stack-size-oxide-asteroid-chunk=Space → Oxide asteroid chunk
 stack-size-promethium-asteroid-chunk=Space → Promethium asteroid chunk
+stack-size-custom-others=Others (custom rules)
 
 [mod-setting-description]
 stack-size-brick=Set the stack size for stone bricks. Default is 100. Minimum is 1. Maximum is 100000.
@@ -171,3 +172,4 @@ stack-size-metallic-asteroid-chunk=Set the stack size for metallic asteroid chun
 stack-size-carbonic-asteroid-chunk=Set the stack size for carbonic asteroid chunks. Default is 1. Minimum is 1. Maximum is 100000.
 stack-size-oxide-asteroid-chunk=Set the stack size for oxide asteroid chunks. Default is 1. Minimum is 1. Maximum is 100000.
 stack-size-promethium-asteroid-chunk=Set the stack size for promethium asteroid chunks. Default is 1. Minimum is 1. Maximum is 100000.
+stack-size-custom-others=Set here any custom rules for other/modded item prototypes. Rules are divided by ";" and are in the format "my-item-prototype=<stacksize>". Minimum recognized value is 1. Maximum is 100000.
diff --git a/CustomStackSize/settings.lua b/CustomStackSize/settings.lua
index 9695fce..375481f 100644
--- a/CustomStackSize/settings.lua
+++ b/CustomStackSize/settings.lua
@@ -20,4 +20,14 @@ for _, category in pairs(stack_list) do
   end
 end
 
+settings_to_add[#settings_to_add + 1] = {
+  type = "string-setting",
+  name = "stack-size-custom-others",
+  setting_type = "startup",
+  default_value = "",
+  allow_blank = true,
+  -- allow_trim = false,
+  order = "za",
+}
+
 data:extend(settings_to_add)