diff --git a/Customizations/JSON/Denomination.ts b/Customizations/JSON/Denomination.ts
index 9ecdf4c53..dc65e4142 100644
--- a/Customizations/JSON/Denomination.ts
+++ b/Customizations/JSON/Denomination.ts
@@ -6,54 +6,57 @@ import Combine from "../../UI/Base/Combine";
 
 export class Unit {
     public readonly appliesToKeys: Set<string>;
-    public readonly denominations : Denomination[];
+    public readonly denominations: Denomination[];
     public readonly defaultDenom: Denomination;
-    constructor(appliesToKeys: string[], applicableUnits: Denomination[]) {
-        this.appliesToKeys = new Set( appliesToKeys);
+    public readonly eraseInvalid : boolean;
+
+    constructor(appliesToKeys: string[], applicableUnits: Denomination[], eraseInvalid: boolean) {
+        this.appliesToKeys = new Set(appliesToKeys);
         this.denominations = applicableUnits;
-this.defaultDenom = applicableUnits.filter(denom => denom.default)[0]
+        this.defaultDenom = applicableUnits.filter(denom => denom.default)[0]
+        this.eraseInvalid = eraseInvalid
     }
 
-    isApplicableToKey(key: string | undefined) : boolean {
-        if(key === undefined){
+    isApplicableToKey(key: string | undefined): boolean {
+        if (key === undefined) {
             return false;
         }
-        
+
         return this.appliesToKeys.has(key);
     }
 
     /**
      * Finds which denomination is applicable and gives the stripped value back
      */
-    findDenomination(valueWithDenom: string) : [string, Denomination] {
+    findDenomination(valueWithDenom: string): [string, Denomination] {
         for (const denomination of this.denominations) {
-          const bare =  denomination.StrippedValue(valueWithDenom)
-            if(bare !== null){
+            const bare = denomination.StrippedValue(valueWithDenom)
+            if (bare !== null) {
                 return [bare, denomination]
             }
-        } 
+        }
         return [undefined, undefined]
     }
 
     asHumanLongValue(value: string): BaseUIElement {
-        if(value === undefined){
+        if (value === undefined) {
             return undefined;
         }
         const [stripped, denom] = this.findDenomination(value)
         const human = denom.human
-        
-        const elems = denom.prefix ? [human, stripped] : [stripped , human];
+
+        const elems = denom.prefix ? [human, stripped] : [stripped, human];
         return new Combine(elems)
-        
+
     }
 }
 
 export class Denomination {
-    private readonly _human: Translation;
-    private readonly alternativeDenominations: string [];
     public readonly canonical: string;
     readonly default: boolean;
     readonly prefix: boolean;
+    private readonly _human: Translation;
+    private readonly alternativeDenominations: string [];
 
     constructor(json: UnitConfigJson, context: string) {
         context = `${context}.unit(${json.canonicalDenomination})`
@@ -77,13 +80,13 @@ export class Denomination {
         this.prefix = json.prefix ?? false;
 
     }
-    
-    get human() : Translation {
+
+    get human(): Translation {
         return this._human.Clone()
     }
 
     public canonicalValue(value: string, actAsDefault?: boolean) {
-        if(value === undefined){
+        if (value === undefined) {
             return undefined;
         }
         const stripped = this.StrippedValue(value, actAsDefault)
@@ -102,10 +105,10 @@ export class Denomination {
      */
     public StrippedValue(value: string, actAsDefault?: boolean): string {
 
-        if(value === undefined){
+        if (value === undefined) {
             return undefined;
         }
-        
+
         if (this.prefix) {
             if (value.startsWith(this.canonical)) {
                 return value.substring(this.canonical.length).trim();
diff --git a/Customizations/JSON/LayoutConfig.ts b/Customizations/JSON/LayoutConfig.ts
index 77487a663..f98d6dde7 100644
--- a/Customizations/JSON/LayoutConfig.ts
+++ b/Customizations/JSON/LayoutConfig.ts
@@ -99,7 +99,7 @@ export default class LayoutConfig {
                 if (AllKnownLayers.sharedLayersJson[layer] !== undefined) {
                     if (json.overrideAll !== undefined) {
                         let lyr = JSON.parse(JSON.stringify(AllKnownLayers.sharedLayersJson[layer]));
-                        return new LayerConfig(Utils.Merge(json.overrideAll, lyr), this.units,`${this.id}+overrideAll.layers[${i}]`, official);
+                        return new LayerConfig(Utils.Merge(json.overrideAll, lyr), this.units, `${this.id}+overrideAll.layers[${i}]`, official);
                     } else {
                         return AllKnownLayers.sharedLayers[layer]
                     }
@@ -190,7 +190,7 @@ export default class LayoutConfig {
 
     }
 
-    private static ExtractUnits(json: LayoutConfigJson, context: string) : Unit[]{
+    private static ExtractUnits(json: LayoutConfigJson, context: string): Unit[] {
         const result: Unit[] = []
         if ((json.units ?? []).length !== 0) {
             for (let i1 = 0; i1 < json.units.length; i1++) {
@@ -220,7 +220,7 @@ export default class LayoutConfig {
                     throw `Multiple units are set as default: they have canonical values of ${defaultSet.map(u => u.canonicalDenomination).join(", ")}`
                 }
                 const applicable = unit.applicableUnits.map((u, i) => new Denomination(u, `${context}.units[${i}]`))
-                result.push(new Unit(                   appliesTo, applicable));
+                result.push(new Unit(appliesTo, applicable, unit.eraseInvalidValues ?? false));
             }
 
             const seenKeys = new Set<string>()
diff --git a/Customizations/JSON/LayoutConfigJson.ts b/Customizations/JSON/LayoutConfigJson.ts
index 4fe7cb7e1..6d079dc94 100644
--- a/Customizations/JSON/LayoutConfigJson.ts
+++ b/Customizations/JSON/LayoutConfigJson.ts
@@ -249,7 +249,15 @@ export interface LayoutConfigJson {
          */
         appliesToKey: string[],
 
+        /**
+         * The possible denominations
+         */
         applicableUnits: UnitConfigJson[]
+        /**
+         * If set, invalid values will be erased in the MC application (but not in OSM of course!)
+         * Be careful with setting this
+         */
+        eraseInvalidValues?: boolean;
     }[]
 
     /**
diff --git a/Logic/FeatureSource/FeaturePipeline.ts b/Logic/FeatureSource/FeaturePipeline.ts
index 2235c87bf..340710503 100644
--- a/Logic/FeatureSource/FeaturePipeline.ts
+++ b/Logic/FeatureSource/FeaturePipeline.ts
@@ -77,16 +77,14 @@ export default class FeaturePipeline implements FeatureSource {
             ]);
 
         merged.features.syncWith(allLoadedFeatures)
-        
-        const source =
-            new WayHandlingApplyingFeatureSource(flayers,
-                new FilteringFeatureSource(
-                    flayers,
-                    locationControl,
-                    selectedElement,
-                    merged
-                ));
-        this.features = source.features;
+
+        this.features = new WayHandlingApplyingFeatureSource(flayers,
+            new FilteringFeatureSource(
+                flayers,
+                locationControl,
+                selectedElement,
+                merged
+            )).features;
     }
 
 }
\ No newline at end of file
diff --git a/Logic/SimpleMetaTagger.ts b/Logic/SimpleMetaTagger.ts
index 6d9491aed..afb0cea47 100644
--- a/Logic/SimpleMetaTagger.ts
+++ b/Logic/SimpleMetaTagger.ts
@@ -94,9 +94,14 @@ export default class SimpleMetaTagger {
                     }
                     const value = feature.properties[key]
                     const [, denomination] = unit.findDenomination(value)
-                    const canonical = denomination.canonicalValue(value)
+                    let canonical = denomination.canonicalValue(value) ?? undefined;
                     console.log("Rewritten ", key, " from", value, "into", canonical)
+                    if(canonical === undefined && !unit.eraseInvalid) {
+                        break;
+                    }
+                    
                     feature.properties[key] = canonical;
+                    break;
                 }
 
             }