What is the Access Key in Users/My Preferences? What is Masking? What is the importance of Masking in Vtiger CRM? What are the features and fields that can be masked in Vtiger CRM? What is the feature availability of the Masking feature in Vtiger CRM? What are the benefits of Masking information in Vtiger CRM? How do I install the Masking add-on in Vtiger CRM? What can an admin user do using the Masking feature? How do I enable the masking feature? How do I set up maskin for roles? How do I set up masking for profiles? How do I set up masking for modules? What is the limitation of the masking feature in Vtiger CRM? How do I restrict access to sensitive data in Vtiger CRM?