You can add custom client-side validation scripts or error messages on an application-wide by overriding the HTML fragment rule UserWorkForm, which is included in the fragment WorkFormStandard, which in turn is included in the HTML code for every user form.
Userworkform is the HTML (containing style ,script)fragment that is loaded whenever a userform is loaded that is any section. So whenever any UI is loaded, it will be loaded at last so any change made in it will get affected overriding other styles or script
UserWorkForm is a HTML Fragment rule that accepts customized Scripts to be executed during the loading of screen. The scripts can be any type, for example in order to customize the Busy Indicator in your application, you can include a script with customized gif image. Similarly we can customize many things. UserWorkForm always loads during the launch of harness and Refreshing of section.