When a field is configured to display "Rich Text", it can contain text spans that are links, use different fonts, or include inline images. Rich Text is described in the reference manual here.
Rich Text is represented as a Lil table, and can be constructed like any other table so long as it has the appropriate columns. For example,
myField.value:insert text font arg with "Apple" "" "theAppleCard" end
Remember, of course, that fields need to be locked for their hyperlinks to be clickable. Unless you define your own link[] handler for a field, clicking a link will call the go[] built-in function with that "arg" value, which conveniently serves either to navigate to cards by name or to prompt the user to open URLs in a new browser tab.
The "RText" utility interface (linked above) offers a number of convenience functions for creating and manipulating Rich Text tables. The "rtext.make[]" function offers a more concise alternative to the above:
myField.value:rtext.make["Apple" "" "theAppleCard"]
In the interactive docs for a variety of modules I use this sort of approach to automatically generate the index in the title card's view[] event handler:
bullet:image["%%IMG0AAYADQAAAAB49Pz8/HgAAAA="] i:select c:key t:value..widgets.title.text where value..widgets.title from deck.cards index.value:raze each row in rows i rtext.make["" "" bullet], rtext.make[" "], rtext.make[("%s\n" format row.t) "mono" row.c] end
Does that help?