When an update becomes available for a particular piece of software, if I run
aptitude changelog <name>
I will see urgency as either low, medium or high.
How is it decided which category a fix falls into? And also, should I treat 'high' to mean 'install asap' and 'medium' to mean, 'install when convenient'?
Is there a best practice to follow on how soon high medium or low fixes should be implemented?