The most common and most likely answer to this crossword clue is the 9 letter word UPPERCASE
I've seen this crossword clue in Independent
U
P
P
E
R
C
A
S
E
More clues leading to the result UPPERCASE
Buddy explains!

The straight part
We know that "Like QC, say" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case like qc, say = uppercase.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 UPPERCASE mean?
UPPERCASE noun- Collective term for the capital letters A, B, C, ... as opposed to the small letters a, b, c, ....
- To convert (text) to upper case.
- Written in upper case; capital