Hi,

I'm not sure what you mean by any Incident table, but you can use UI Policy for this to set those fields as mandatory. Client script is really recommended ONLY IF the UI Policy can't work for you.

However, here is the documentation on using setMandatory that you can use in client script:

https://developer.servicenow.com/app.do#!/api_doc?v=newyork&id=r_GlideFormSetMandatory_String_Boolea...

Please mark reply as Helpful/Correct, if applicable. Thanks!