Before we venture to learn form customization tool, click [here](https://kb.frappe.io/kb/customization/form-architecture) to understand the architecture of forms in ERPNext. It shall help you in using Customize Form tool more efficiently.
Customize Form is the tool which allows user to customize the property of standard fields as per the requirement. Let's assume we need to set Project Name field as mandatory in the Sales Order form. Following are the steps which shall be followed to achieve this.
####Step 1: Go to Customize Form
You can go to Customize Form from:
> Setup >> Customize >> Customize Form
System Manager will find Customize Form option in the Sales Order list (or any other form for that matter) view as well.
On selecting Doctype/table, you will have all the fields of the table updated as rows in the Customize Form table. You should drill down to field you need to work on, Project Name in this case.
On clicking Project Name row, fields to set various property for this field will be shown. To Customize the mandatory property for a field, there is a field called "Mandatory". Checking this field will set Project Name field as mandatory in the Quotation form.
Before checking Sales Order form, you should clear cache and refresh browser tab for customization to take effect.
For Customize Form, you can also allow attachments, set max number of attachments and set the default Print Format.
>Note: Though we want you to do everything you can to customize your ERP based on your business needs, we recommend that you do not make “wild” changes to the forms. This is because, these changes may affect certain operations and may mess up your forms. Make small changes and see its effect before doing some more.
Following are the properties which you can customize for a specific field from Customize Form.