The default forms configuration is specified in the
        <configRootShare>/classes/alfresco/share-form-config.xml file.
      This file contains all the default controls and constraint handlers for the SkyVault content
      model and the form configuration for the cm:content and
        cm:folder types. This file also contains an example of configuring the
        cm:content type. 
    You should apply all your forms customizations to a custom configuration file. To configure forms for the Share application, use the custom configuration file named share-config-custom.xml.
- Open the <web-extension>/share-config-custom.xml file.
 - Modify the forms configuration settings using the XML configuration syntax.
 - Save the file without the .sample extension.