Use case
If Technicians want to hide Asset field during template loading, then the same can be achieved using Execute Script option in Field and Form Rules.
Solution
Edit the incident/service template from which the asset needs to be hidden, choose Field & Form Rule tab. Create a rule "On Load" with the below script.
jQuery('[name=selectedCIs]').parents('div.mb0').hide();
//Hiding the asset in details page (In-line Edit)
try{
jQuery('#multiasset').parents().eq(0).hide();
}catch(e){}
and save.
This will hide the asset when the template is selected.