The ‘Visible’ attribute on a variable accepts a boolean script. This script is evaluated at runtime to determine if the variable should be displayed. Writing a script like `gs.hasRole(‘itil’)` is the standard, declarative way to control variable visibility based on roles directly within the variable’s configuration. UI Policies and Client Scripts are more complex and less direct for this simple role-based visibility, and ACLs control data access, not UI visibility on a catalog item.

The most efficient first step is to check the script’s condition. If the condition field is populated, the script will only run when that condition evaluates to true. A simple oversight in the condition logic is a very common reason for a client script not to fire. Checking this is quicker than adding debug logs or diving into the script debugger immediately.

A reference qualifier is the declarative, server-side method for dynamically filtering the available records in a reference variable. It uses a condition (which can include `current.variables.department`) to filter the list at the database level. This is more performant and cleaner than using an onChange client script to manually manipulate a list of choices, as it leverages platform-native filtering.

In email notification templates for catalog items, the correct syntax to reference a variable value is the Jelly Expression Language (JEL) format: `$[variables.variable_name]`. The `${…}` syntax is used in other contexts, like in mail scripts or some UI policies, but not within the HTML/Message body of a catalog notification template.

The best practice is to use a workflow (or now, a Flow) on the Requested Item (sc_req_item) record. The record producer submits a single RITM. A subsequent workflow or flow, triggered on the RITM’s insertion, can then create the two separate task records (like CHG and custom project task). This keeps the business logic out of the client-side UI script, making it more maintainable, scalable, and easier to debug. Direct GlideRecord inserts in client scripts are generally discouraged for this purpose.

The most appropriate place is the ‘Default value’ script attribute of the variable itself. This is a declarative field designed specifically for this purpose. The script (e.g., `gs.getUser().getDepartment()`) runs when the variable is rendered, setting the default dynamically. Using an onLoad script would work but adds unnecessary code overhead when a built-in, purpose-built attribute exists.

The System Log (syslog) is the primary repository for server-side script errors and exceptions. When a business rule, script include, or workflow script activity fails, it typically writes a stack trace and error message here. The Workflow Execution Log shows the path taken but not necessarily script error details. Transaction and Email logs are for other specific purposes.

The most robust validation should be in a server-side business rule (before insert) on the target table (e.g., the custom license request table). This ensures the check happens reliably on the server, regardless of how the record is created (UI, API, integration). Client-side (onSubmit) validation can improve user experience but can be bypassed; server-side validation is mandatory for data integrity.

ServiceNow provides a specific ‘Email’ variable type. Changing the ‘Type’ from ‘Single Line Text’ to ‘Email’ automatically applies built-in client and server-side format validation for email addresses. This is the simplest and most correct approach. Using a custom validation script is unnecessary when a dedicated type exists.

The ‘Visible’ attribute on a variable accepts a boolean script. This script is evaluated at runtime to determine if the variable should be displayed. Writing a script like `gs.hasRole(‘itil’)` is the standard, declarative way to control variable visibility based on roles directly within the variable’s configuration. UI Policies and Client Scripts are more complex and less direct for this simple role-based visibility, and ACLs control data access, not UI visibility on a catalog item.0