quite a lot of stuff, can't list them all here (approaching 1.9)

scripts/0-group_manager.lua

@@ -0,0 +1,22 @@
+hooks.registered_groups = {}
+
+function hooks.group(group)
+    if hooks.registered_groups[group] then
+        local ok, generated, b, c, d = pcall(hooks.registered_groups[group], group)
+        if ok then return generated, b, c, d
+        else
+            print(generated)
+            return false, 0, 0, 0
+        end
+    end
+    return false, 0, 0, 0
+end
+
+---@param designator string
+---@param handler function
+function rds.ext.register_group(designator, handler)
+    for i = 1, #designator do
+        local char = designator:sub(i, i)
+        hooks.registered_groups[char] = handler
+    end
+end