You can hyperlink on your Reddit posts or comments by using the icon that looks like a chain, which is available on both desktop and mobile devices.

You can make a Google Form public, or open to respondents or collaborators, by adjusting its sharing settings. Here's how to ...

But why can't any real-world object -- with or without a code -- be enriched by virtual information, accessible through a cell phone screen, a visor, or, looking even further into the future, ...