Resume information. There have been several attempts, but none have become an accepted standard.

When I was a consultant, this was the one standard I longed for the most. A data file where I could put all of my information, and then filter and format it for each application. But ultimately, I wanted to be able to submit the information in a standardised format - without having to re-enter it endlessly into crappy web forms.

I think things have gotten better today, but at the cost of a reliance on a monopoly (LinkedIn). And I'm not still in that sort of job market. But I think that desire was so strong it'll last me until I'm in my grave.