diff --git a/frontends/mdr-frontend/src/components/Dialog/Dialog.tsx b/frontends/mdr-frontend/src/components/Dialog/Dialog.tsx
index 3893f71..af9f920 100644
--- a/frontends/mdr-frontend/src/components/Dialog/Dialog.tsx
+++ b/frontends/mdr-frontend/src/components/Dialog/Dialog.tsx
@@ -45,6 +45,7 @@ export interface DialogField {
   accept?: string;
   inputMode?: InputMode;
   pattern?: string;
+  patternErr?: string;
 }
 
 export interface DialogItem {
@@ -92,6 +93,10 @@ export const CrudDialog: React.FC<CrudDialogProps> = ({
           nextParams.BaseDataModelId = null;
         }
       }
+      // # Disabled pattern validation here; now handled on handleCreateOrEdit
+      // if (field.pattern && createParams[field.name] && !new RegExp(field.pattern).test(createParams[field.name])) {
+      //   setCreateError(`The following fields have invalid values:\n > ${field.patternErr}`);
+      // }
       return nextParams;
     });
   };
@@ -111,6 +116,12 @@ export const CrudDialog: React.FC<CrudDialogProps> = ({
       setCreateError(`Please complete all required fields: ${missingFields.join(", ")}`);
       return;
     }
+
+    const regexFields = fields.filter((f) => f.pattern && createParams[f.name] && !new RegExp(f.pattern).test(createParams[f.name]));
+    if (regexFields.length) {
+      setCreateError(`The following fields have invalid values:\n > ${regexFields.map(f => f.patternErr).join("\n > ")}`);
+      return;
+    }
   
     setDisableSubmitForm(true);
     if (isEditMode && itemToEdit) {
@@ -228,7 +239,7 @@ export const CrudDialog: React.FC<CrudDialogProps> = ({
           {createError && (
             <>
               <br /><br />
-              <Text color="red" size="2" mb="3">
+              <Text color="red" size="2" mb="3" style={{ whiteSpace: "pre-line" }}>
                 {createError}
               </Text>
             </>
@@ -298,6 +309,7 @@ export const CrudDialog: React.FC<CrudDialogProps> = ({
                     onChange={(e) => handleFieldValueChange(field, e.target.value) }
                     inputMode={field.inputMode}
                     pattern={field.pattern}
+                    title={field.patternErr ?? ""}
                     readOnly={field.readOnly || (isEditMode && field.name === "CreationDate")}
                   />
                 )}
diff --git a/frontends/mdr-frontend/src/components/ModelExplorer/CreateOptFields.tsx b/frontends/mdr-frontend/src/components/ModelExplorer/CreateOptFields.tsx
index 9d60f66..1e97d76 100644
--- a/frontends/mdr-frontend/src/components/ModelExplorer/CreateOptFields.tsx
+++ b/frontends/mdr-frontend/src/components/ModelExplorer/CreateOptFields.tsx
@@ -13,12 +13,21 @@ export const entityCreateFields = (model: any): DialogField[] => {
       hidden: true,
       defaultValue: model?.Id,
     },
-    { name: "Name", type: "text" as const, label: "Name", required: true },
+    {
+      name: "Name",
+      type: "text" as const,
+      label: "Name",
+      required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Name must start with a letter and contain only letters, numbers, and underscores.",
+    },
     {
       name: "UniqueName",
       type: "text" as const,
       label: "Unique Name",
       required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Unique Name must start with a letter and contain only letters, numbers, and underscores.",
     },
     { name: "Description", type: "text" as const, label: "Description" },
     {
@@ -90,12 +99,21 @@ export const attributeCreateFields = (model: any, valueSetId: string | number |
       hidden: true,
       defaultValue: valueSetId?.toString(),
     },
-    { name: "Name", type: "text" as const, label: "Name", required: true },
+    {
+      name: "Name",
+      type: "text" as const,
+      label: "Name",
+      required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Name must start with a letter and contain only letters, numbers, and underscores.",
+    },
     {
       name: "UniqueName",
       type: "text" as const,
       label: "Unique Name",
       required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Unique Name must start with a letter and contain only letters, numbers, and underscores.",
     },
     {
       name: "DataType",
@@ -173,7 +191,14 @@ export const valueSetCreateFields = (model: any): DialogField[] => {
       hidden: true,
       defaultValue: model?.Id,
     },
-    { name: "Name", type: "text" as const, label: "Name", required: true },
+    {
+      name: "Name",
+      type: "text" as const,
+      label: "Name",
+      required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Name must start with a letter and contain only letters, numbers, and underscores.",
+    },
     { name: "Description", type: "text" as const, label: "Description" },
     {
       name: "Use Considerations",
@@ -223,6 +248,8 @@ export const valueCreateFields = (model: any): DialogField[] => {
       type: "text" as const,
       label: "Value Name",
       required: true,
+      pattern: "^[A-Za-z][A-Za-z0-9_]*$",
+      patternErr: "Value Name must start with a letter and contain only letters, numbers, and underscores.",
     },
     { name: "Description", type: "text" as const, label: "Description" },
     {