The most common and most likely answer to this crossword clue is the 10 letter word CHARACTERS
I've seen this crossword clue in The Guardian
C
H
A
R
A
C
T
E
R
S
Buddy explains!
The straight part
We know that "Letters/interesting people" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case letters/interesting people = characters.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CHARACTERS mean?
CHARACTERS noun- A being involved in the action of a story.
- A distinguishing feature; characteristic; trait; phene.
- A complex of traits marking a person, group, breed, or type.
- Strength of mind; resolution; independence; individuality; moral strength.
- A unique or extraordinary individual; a person characterized by peculiar or notable traits, especially charisma.
- A written or printed symbol, or letter.
- Style of writing or printing; handwriting; the particular form of letters used by a person or people.
- A secret cipher; a way of writing in code.
- One of the basic elements making up a text file or string: a code representing a printing character or a control character.
- A person or individual, especially one who is unknown or raises suspicions.
- A complex number representing an element of a finite Abelian group.
- Quality, position, rank, or capacity; quality or conduct with respect to a certain office or duty.
- The estimate, individual or general, put upon a person or thing; reputation.
- A reference given to a servant, attesting to his/her behaviour, competence, etc.
- Personal appearance.