What is the difference between :raw-value and :title?

[mbork]

Hi all,

I am reading the Org element API docs and I don't understand the
difference between :raw-value of a headline and its :title.  I performed
a few experiments with putting various things in the headline
(timestamps, links, markup) to find a case where these two differ, but I
could not.

The :title is described as a "secondary string".  What is a "secondary
string"?  Maybe if I knew that, I would understand the difference...?

TIA,

-- 
Marcin Borkowski
https://mbork.pl
https://crimsonelevendelightpetrichor.net/