The four categories, from the least to the most intrusive, are:

Next Chrome 80 Will Adopt Less Annoying Website Notification UI

Notification requests in Chrome 80 will be far less annoying

the possibility of implementing less intrusive methods;

Therefore, they appear with less intrusive advertisement.

Previous Chrome 80 will finally make notification requests less annoying

Alternatives exist that are less intrusive and coercive.

other available less invasive investigative techniques have been considered;

These auctions require less infrastructure and are less intrusive.

less invasive investigative techniques have been considered;

These notifications are less intrusive and much cheaper than SMS.

other available less invasive investigative techniques have been considered;

ii. other less intrusive investigative techniques have been exhausted;

other available less invasive investigative techniques have been considered;

the possibility of implementing less intrusive methods;