See the docs here.. 
Runtime Modes | Umbraco CMS
Umbraco:CMS:RuntimeMinification:CacheBuster is set to a fixed cache buster like Version or AppDomain ;
I normally stick to Version (without specifiy the version as then UmbracoCore generates a hash based around your www project assembly version and the umbraco version… you are incrementing assembly version on each release though??? 
)