diff --git a/common/build.rs b/common/build.rs
index 20be794..2440bb0 100644
--- a/common/build.rs
+++ b/common/build.rs
@@ -12,6 +12,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             ".komp_ac.table_validation.CharacterLimits",
             "#[derive(serde::Serialize, serde::Deserialize)]",
         )
+        .type_attribute(
+            ".komp_ac.table_validation.DisplayMask",
+            "#[derive(serde::Serialize, serde::Deserialize)]",
+        )
         .type_attribute(
             ".komp_ac.table_validation.TableValidationResponse",
             "#[derive(serde::Serialize, serde::Deserialize)]",
diff --git a/common/proto/table_validation.proto b/common/proto/table_validation.proto
index 1952307..f7ef833 100644
--- a/common/proto/table_validation.proto
+++ b/common/proto/table_validation.proto
@@ -23,9 +23,10 @@ message FieldValidation {
   CharacterLimits limits = 10;
   // Future expansion:
   // PatternRules pattern = 11;
-  // DisplayMask mask = 12;
+  DisplayMask mask = 3;
   // ExternalValidation external = 13;
   // CustomFormatter formatter = 14;
+  bool required = 4;
 }
 
 // Character length counting mode
@@ -49,6 +50,13 @@ message CharacterLimits {
   CountMode countMode = 4; // defaults to CHARS if unspecified
 }
 
+// Mask for pretty display
+message DisplayMask {
+  string pattern = 1;              // e.g., "(###) ###-####" or "####-##-##"
+  string input_char = 2;           // e.g., "#"
+  optional string template_char = 3; // e.g., "_"
+}
+
 // Service to fetch validations for a table
 service TableValidationService {
   rpc GetTableValidation(GetTableValidationRequest)
diff --git a/common/src/proto/descriptor.bin b/common/src/proto/descriptor.bin
index d552ef0..61967eb 100644
Binary files a/common/src/proto/descriptor.bin and b/common/src/proto/descriptor.bin differ
diff --git a/common/src/proto/komp_ac.table_validation.rs b/common/src/proto/komp_ac.table_validation.rs
index 2fc6e6f..dbd6ba4 100644
--- a/common/src/proto/komp_ac.table_validation.rs
+++ b/common/src/proto/komp_ac.table_validation.rs
@@ -23,14 +23,16 @@ pub struct FieldValidation {
     #[prost(string, tag = "1")]
     pub data_key: ::prost::alloc::string::String,
     /// Current: only CharacterLimits. More rules can be added later.
-    ///
-    /// Future expansion:
-    /// PatternRules pattern = 11;
-    /// DisplayMask mask = 12;
-    /// ExternalValidation external = 13;
-    /// CustomFormatter formatter = 14;
     #[prost(message, optional, tag = "10")]
     pub limits: ::core::option::Option<CharacterLimits>,
+    /// Future expansion:
+    /// PatternRules pattern = 11;
+    #[prost(message, optional, tag = "3")]
+    pub mask: ::core::option::Option<DisplayMask>,
+    /// ExternalValidation external = 13;
+    /// CustomFormatter formatter = 14;
+    #[prost(bool, tag = "4")]
+    pub required: bool,
 }
 /// Character limit validation (Validation 1)
 #[derive(serde::Serialize, serde::Deserialize)]
@@ -49,6 +51,20 @@ pub struct CharacterLimits {
     #[prost(enumeration = "CountMode", tag = "4")]
     pub count_mode: i32,
 }
+/// Mask for pretty display
+#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct DisplayMask {
+    /// e.g., "(###) ###-####" or "####-##-##"
+    #[prost(string, tag = "1")]
+    pub pattern: ::prost::alloc::string::String,
+    /// e.g., "#"
+    #[prost(string, tag = "2")]
+    pub input_char: ::prost::alloc::string::String,
+    /// e.g., "_"
+    #[prost(string, optional, tag = "3")]
+    pub template_char: ::core::option::Option<::prost::alloc::string::String>,
+}
 #[derive(serde::Serialize, serde::Deserialize)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct UpdateFieldValidationRequest {
diff --git a/server/src/table_validation/get/service.rs b/server/src/table_validation/get/service.rs
index a04807f..43e82c7 100644
--- a/server/src/table_validation/get/service.rs
+++ b/server/src/table_validation/get/service.rs
@@ -40,12 +40,16 @@ impl TableValidationService for TableValidationSvc {
                     // Set the data_key from the database row
                     fv.data_key = r.data_key;
                     
-                    // Skip if limits are all zero
-                    if let Some(lims) = &fv.limits {
-                        if lims.min == 0 && lims.max == 0 && lims.warn_at.is_none() {
-                            continue;
-                        }
-                    }
+                    // Keep entries that have either meaningful limits or a mask
+                    let has_meaningful_limits = fv
+                        .limits
+                        .as_ref()
+                        .map_or(false, |l| l.min > 0 || l.max > 0 || l.warn_at.is_some());
+                    let has_mask = fv.mask.is_some();
+                    if !has_meaningful_limits && !has_mask {
+                        continue;
+                    }                    
+
                     fields_out.push(fv);
                 }
                 Err(e) => {