When you have many notifications, listing them all is just drudgery. If you would like to figure out what caused a notification to be displayed, you would like to be able to query just that specific notification.
For example, if you have a notification set up for a pattern which matches just a partial IP address, finding out what exactly that pattern was will currently require you to search chat for your original @hal notify, sometimes with creative search terms.
The proposal here, then, is to accept a string after @hal notifications or @hal my notifications and display only the patterns which match that string.