diff --git a/src/main.ts b/src/main.ts
index 8a17fd8..1225ef5 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -11,6 +11,9 @@ const DEFAULT_SETTINGS: CheckboxSyncPluginSettings = {
   xOnlyMode: true,
   enableAutomaticParentState: true,
   enableAutomaticChildState: true,
+  checkedSymbols: ['x'],
+  uncheckedSymbols: [' '],
+  unknownSymbolPolicy: 'checked', 
 };
 
 export default class CheckboxSyncPlugin extends Plugin {
diff --git a/src/types.ts b/src/types.ts
index ed447ff..86c1b63 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,5 +1,10 @@
+export type UnknownSymbolPolicy = 'checked' | 'unchecked' | 'ignore';
+
 export interface CheckboxSyncPluginSettings {
   xOnlyMode: boolean;
   enableAutomaticParentState: boolean;
   enableAutomaticChildState: boolean;
+  checkedSymbols: string[];
+  uncheckedSymbols: string[];
+  unknownSymbolPolicy: UnknownSymbolPolicy;
 }
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