The phrase "a new section in" is correct and usable in written English.
It can be used when referring to the addition or creation of a new part within a larger document, book, or project.
Example: "In the latest edition of the manual, we have included a new section in the chapter on safety procedures."
Alternatives: "an additional part in" or "a fresh segment in".
The commission has dedicated a new section in the guides specifically to handling issues surrounding certifications and seals of approval.
I saw Profumo briefly some months ago when Sir John Major was opening a new section in Toynbee Hall named after Profumo.
A new section in the 3 1/2-hour exam, which has until now asked only multiple choice questions, will require written essays to demonstrate students' analytical ability.
For individuals — those with a legacy to protect, or secrets to hide — it might be time to consider a new section in the will.
The novel simply breaks here and begins a new section in which Konwicki and his friends are back in line, waiting endlessly for a shipment of goods and knowing that word of the shipment is probably just a rumor.
For the first time in 70 years, we launch a new section in the paper devoted to one country, examining China's growing economic might, its internal transformation and its impact on the world.
Not the Roma, who in spite of a new Section 30 in their neck of the woods were still being publicly gregarious in a foreign language.
Once a match has been made, a new section appears in the user's profile section showing the badges of the networks they belong to.
Facebook is going to create a new news section in its video streaming platform Facebook Watch to feature breaking news stories.
Potential investment in a new section of M4 motorway in the Newport area has not been universally welcomed.
The crowd cheered each time a new section was put in place.
