After clicking "Dig" the URL contains the information you have entered and can therefore be shared.
This also means you can select your preferred type, options and nameservers (but leave hostnames blank) and click "Dig". Bookmark the following page, and it will contain your settings. It is also possible to put your query in the URL as http://digwebinterface.com/hostname/type/nameserver. Hostname is required but type and nameserver are optional.
An underlined letter indicates a keyboard shortcut. Press Alt + (Shift +) the letter to (un)select the corresponding option. The shortcut for the "Dig" button is Alt + (Shift +) Q. To reset the form press Alt + 0.
By holding the cursor over an option, you will get an explanation of the usage. The same can be done with TTLs and record types in the output. Clicking a record type will take you to the appropriate RFC.
Clicking on a hostname in the output will add it to the hostnames list. Clicking on a nameserver will add it to the "Specify myself" list.