Storing URL's for Reuse
This article describes the method for setting up reusable external links or URL's that works in Heretto.
External URL's can be stored as conrefs and referenced throughout your content.
The benefits to this are that it's easy to update URL's across the site when marketing or another departments updates the online site.
The downside to this is that when you store them as conrefs, you're limited on presentation.
For best practice, store URL's in in a table in a single warehouse topic. See Global URL Warehouse.
Warning: Although it may be possible in the "world of DITA" to add URL's to keyrefs, they do not resolve in the Heretto portal. They display an error to the reader.
Heretto's documentation lists additional best practices you may want to reference.