The most common and most likely answer to this crossword clue is the 2 plus 4 letter word IN LINE
I've seen this crossword clue in Financial Times
I
N
L
I
N
E
More clues leading to the result IN LINE
Buddy explains!
The straight part
We know that "Queuing/under control" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case queuing/under control = in line.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 IN LINE mean?
IN LINE adjective- Consisting of parts arranged in a single line.
- (writing) Inserted in the flow of a text.
- (of source code) Of a different language than the outer enclosing code.
- (Cascading Style Sheets) Of a style: inserted in the style attribute of an HTML element instead of in a separate stylesheet.