Instance window title
Another way of telling instances apart by the browser tab is to have unique window titles. This approach can be useful if you have many tabs open and you're sifting through them by name.
However, it's impact is minimal as the ends of window titles are usually cut off at the end.
Note: Custom window titles are not visible on the Service Portal.
To quote ServiceNow:
These properties are used to set the window title as follows:
glide.product.name
glide.product.descriptionIf glide.product.name is blank, then the ServiceNow name is used as the product name for the window title.
Here's how the page titles look out-of-the-box.
Here's an example of instance-specific "glide.product.name" of "ServiceNow DEV". You can see how it is visible in the first tab but it is cut-short in the other tabs.