rTextRange differs from NotesRichTextRange as it is result of text search and is used as "text selection" either to replace the text or to navigate returned text fragments and associated rich text elements. NotesRichTextRange is used more in navigation navigation context.
At the same time it is also possible construct
rTextRange in the same manner as NotesRichTextRange, i.e. providing start and end elements.
rTextRange may be used in similar way as NotesRichTextRange to set style of rich text elements although rtLibrary provides several other methods to apply style. An alternative way is to navigate rich text item using different navigation methods provided by
rtContainer (and any - to navigate it's content) and apply style(s) one by one.
rTextRange provides Insert method that allows directly overwrite text of the range or combined with Collapse method to insert text or objects at either end of the range. It also has Collection property that returns all text elements in the range (not only the first one).