diff --git a/cypress/integration/rendering/erDiagram.spec.js b/cypress/integration/rendering/erDiagram.spec.js
index 8e8946170..c72df49b6 100644
--- a/cypress/integration/rendering/erDiagram.spec.js
+++ b/cypress/integration/rendering/erDiagram.spec.js
@@ -182,6 +182,20 @@ describe('Entity Relationship Diagram', () => {
     cy.get('svg');
   });
 
+  it('should render entities with length in attributes type', () => {
+    renderGraph(
+      `
+    erDiagram
+        CLUSTER {
+          varchar(99) name
+          string(255) description 
+        }
+      `,
+      { logLevel: 1 }
+    );
+    cy.get('svg');
+  });
+
   it('should render entities and attributes with big and small entity names', () => {
     renderGraph(
       `
diff --git a/demos/er.html b/demos/er.html
index 06fbf020e..124311a03 100644
--- a/demos/er.html
+++ b/demos/er.html
@@ -40,7 +40,7 @@ erDiagram
       string city
       string region
       string state
-      string postal_code
+      string(5) postal_code
       string country
       }
 
diff --git a/docs/syntax/entityRelationshipDiagram.md b/docs/syntax/entityRelationshipDiagram.md
index 9b938bc36..4f33b1edc 100644
--- a/docs/syntax/entityRelationshipDiagram.md
+++ b/docs/syntax/entityRelationshipDiagram.md
@@ -230,7 +230,7 @@ erDiagram
     }
 ```
 
-The `type` and `name` values must begin with an alphabetic character and may contain digits, hyphens or underscores. Other than that, there are no restrictions, and there is no implicit set of valid data types.
+The `type` and `name` values must begin with an alphabetic character and may contain digits, hyphens, underscores, parentheses and square brackets. Other than that, there are no restrictions, and there is no implicit set of valid data types.
 
 #### Attribute Keys and Comments
 
@@ -244,11 +244,12 @@ erDiagram
         string registrationNumber
         string make
         string model
+        string[] parts
     }
     PERSON ||--o{ NAMED-DRIVER : is
     PERSON {
         string driversLicense PK "The license #"
-        string firstName
+        string(99) firstName "Only 99 characters are allowed"
         string lastName
         int age
     }
@@ -263,11 +264,12 @@ erDiagram
         string registrationNumber
         string make
         string model
+        string[] parts
     }
     PERSON ||--o{ NAMED-DRIVER : is
     PERSON {
         string driversLicense PK "The license #"
-        string firstName
+        string(99) firstName "Only 99 characters are allowed"
         string lastName
         int age
     }
diff --git a/packages/mermaid/src/diagrams/er/parser/erDiagram.jison b/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
index f0411fd72..bd8dc20f0 100644
--- a/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
+++ b/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
@@ -31,7 +31,7 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 <block>\s+                      /* skip whitespace in block */
 <block>\b((?:PK)|(?:FK))\b      return 'ATTRIBUTE_KEY'
 <block>(.*?)[~](.*?)*[~]        return 'ATTRIBUTE_WORD';
-<block>[A-Za-z][A-Za-z0-9\-_\[\]]*  return 'ATTRIBUTE_WORD'
+<block>[A-Za-z][A-Za-z0-9\-_\[\]\(\)]*  return 'ATTRIBUTE_WORD'
 <block>\"[^"]*\"                return 'COMMENT';
 <block>[\n]+                    /* nothing */
 <block>"}"                      { this.popState(); return 'BLOCK_STOP'; }
diff --git a/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js b/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
index 43bc13e6d..e472f5122 100644
--- a/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
+++ b/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
@@ -214,6 +214,19 @@ describe('when parsing ER diagram it...', function () {
     expect(entities[entity].attributes.length).toBe(2);
   });
 
+  it('should allow an entity with attribute that is a limited length string', function () {
+    const entity = 'BOOK';
+    const attribute1 = 'character(10) isbn FK';
+    const attribute2 = 'varchar(5) postal_code "Five digits"';
+
+    erDiagram.parser.parse(`erDiagram\n${entity} {\n${attribute1}\n${attribute2}\n}`);
+    const entities = erDb.getEntities();
+    expect(Object.keys(entities).length).toBe(1);
+    expect(entities[entity].attributes.length).toBe(2);
+    expect(entities[entity].attributes[0].attributeType).toBe('character(10)');
+    expect(entities[entity].attributes[1].attributeType).toBe('varchar(5)');
+  });
+
   it('should allow an entity with multiple attributes to be defined', function () {
     const entity = 'BOOK';
     const attribute1 = 'string title';
diff --git a/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md b/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
index c666877c5..d83fd4b09 100644
--- a/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
+++ b/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
@@ -160,7 +160,7 @@ erDiagram
     }
 ```
 
-The `type` and `name` values must begin with an alphabetic character and may contain digits, hyphens or underscores. Other than that, there are no restrictions, and there is no implicit set of valid data types.
+The `type` and `name` values must begin with an alphabetic character and may contain digits, hyphens, underscores, parentheses and square brackets. Other than that, there are no restrictions, and there is no implicit set of valid data types.
 
 #### Attribute Keys and Comments
 
@@ -174,11 +174,12 @@ erDiagram
         string registrationNumber
         string make
         string model
+        string[] parts
     }
     PERSON ||--o{ NAMED-DRIVER : is
     PERSON {
         string driversLicense PK "The license #"
-        string firstName
+        string(99) firstName "Only 99 characters are allowed"
         string lastName
         int age
     }