Use client script or dictionary to make a field mandatory?

[Suggy]

I have a simple use case - on a NEW incident form, make the 'DESCRIPTION' field as mandatory so that user fills it and only then can submit the form. This is my only requirement (dont care about API's/integrations).

Also note - there is only 1 VIEW configured for incident form and description field is shown in this view.

Question - which is the preferred solution and why?

Use [onLoad client script/UI policy] OR [make it mandatory in Dictionary]

[Runjay Patel]

Hi @Suggy ,

UI Policy would be the right choice for this requirement.

Why - As per ServiceNow best practice we should avoid writing code if configuration enough to achieve the requirement.

Client Script: We need to write code make filed mandatory.

At Dictionary Level: Not recommended, if in future if you require it mandatory on conditional basis then you will not able to do.

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[Pavithra0812]

The Description field in the Incident table is inherited from the Task (Parent) table. If you mark this field as mandatory in the dictionary, it will become mandatory for all child tables as well.

To make the field mandatory specifically for the Incident table (and not for all child tables), you can use a dictionary override. Follow these steps:

1. Navigate to the Dictionary Override related list in the dictionary entry.
2. Choose the table (Incident) where you want to apply the override.
3. Check the Override mandatory option and set Mandatory to true.

[Dr Atul G- LNG]

Hi @Suggy 

UI policy is best, as it is No Code / low code and will not increase the technical debt.

[Anand Kumar P]

Hi @Suggy ,

Preferred ui policy no scripting with customisation we can achieve.

1)Dictionary:Always take precedence over ui policy and client scripts.

Use for global and non-conditional properties like mandatory or read-only, which apply across all interfaces.

Cannot handle conditional logic, its properties override UI Policies and Client Scripts unless explicitly set.

2. UI Policies: Executes after client script.

Use for conditional behavior on forms (e.g., make a field mandatory or visible based on other field values).

Must explicitly override Dictionary properties (e.g., set Mandatory = false if hidden).

3. Client Scripts

Use for complex or advanced logic that cannot be achieved with UI Policies (e.g., custom validation or dynamic field calculations).

Requires scripting knowledge and can impact performance if not optimized.

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0778442

If my response helped, please mark it as the accepted solution ✅ and give a thumbs up👍.
Thanks,
Anand