# first.items[].content
Well, the other obvious facet to DOI is the convenience factor of the short codes, which take up less space & are more uniform in a list of citations.

But that's not really an intrinsic part of the system, it's just an URL-shortening service, operated by one of the pay-to-play vendors.

But URL-shortener services don't last for eternity.

I've got a detailed explanation about why bookmarked that you should read at ur1.ca/N0p3

# first.items[].contentMap.en
Well, the other obvious facet to DOI is the convenience factor of the short codes, which take up less space & are more uniform in a list of citations.

But that's not really an intrinsic part of the system, it's just an URL-shortening service, operated by one of the pay-to-play vendors.

But URL-shortener services don't last for eternity.

I've got a detailed explanation about why bookmarked that you should read at ur1.ca/N0p3