It seems the proper name in journalism industry is redletter:
source: The News Manual
An important breaking news story. From the newspaper practice of highlighting an exclusive, breaking news story in red type.
source: Journalism.uk
Redletter - Exclusive, breaking news coverage of a major news event,
printed in red type.
Doing a search on Google, it seems this comes from Red Letter, with 2 possible disambiguation meanings:
- Red Letter Day
A red letter day (sometimes hyphenated as red-letter day or called
scarlet day in academia) is any day of special significance or
opportunity. Its roots are in classical antiquity; for instance,
important days are indicated in red in a calendar dating from the
Roman Republic (509–27 BC). In medieval manuscripts, initial capitals
and highlighted words (known as rubrics) were written in red ink. The
practice was continued after the invention of the printing press,
including in Catholic liturgical books. Many calendars still indicate
special dates and holidays in red instead of black.
- Red letter edition
Red letter edition bibles are those in which the Dominical words—those
spoken by Jesus Christ, commonly only those spoken during His
corporeal life on Earth—are printed rubricated, in red ink. This is a
modern practice derived from the art and Roman Catholic practice in
mediaeval scriptoria of rubricating headings, leading letters of
sectional text, and words of text in manuscripts for emphasis, similar
to italicization
User Testing
With the help of the PM, I surveyed several of the editors (12 editors, 11 completed answers) using open answers and they answered the block should be named as "breaking news block" or "breaking news splash", or "splash block".
After that, I did a moderated test with 2 questions:
- asked what would they think if they see the word redletter. Answers were unanimous: yes, they recognize that word without a doubt.
- Asked about what kind of UI element they would expect from that word, all answers were: a featured breaking news with prominent visuals (size, typography, imagery, etc.)
Additionally, they all expect the color red to be there somewhere. Most answers specifically said: White text title on red background. This is interesting because we didn't consider the color, which is very different to the blue the element will use according to UI provided. I guess it's something we'll need to test out as well