Modifying the existing fields
Most of the properties of the system and custom fields can be modified after the field has been created. It is worth reminding ourselves that there are several important properties that cannot be modified.
The field properties that cannot be modified are as follows:
• Name: The display name can be modified but the schema name cannot.
• Datatype: If you need to change the datatype that you will need for deleting the field and creating a new field with the appropriate datatype.
• Format: The format cannot be modified for most datatypes, however, the format of the date and time fields can be modified.
• Field security: This can be applied to the custom fields, but cannot be applied to the system fields.

Creating custom fields
Microsoft Dynamics CRM 2011 provides a user interface that enables customizers to create custom fields easily.
To create a custom field, perform the following steps:
1. In the navigation pane, click on Settings.
2. In the Customization group, click on Customizations, and then click on Customize the System to open the default solution.
3. Expand the Entities component and expand the entity that you want to customize.
4. Click on the Fields sub-component and then click on New.
5. Specify the field properties according to your requirements.
6. Click on Save and Close.


Once the field has been saved, it is available to:
• Users through Advanced Find, Report Wizard, Export to Excel, user views, and charts
However, the field will not appear on a form or a system view until you add the field to a form or system view, and publish the entity.