The most common and most likely answer to this crossword clue is the 6 letter word BLANKS
I've seen this crossword clue in The Daily Telegraph
B
L
A
N
K
S
More clues leading to the result BLANKS
Buddy explains!
The straight part
We know that "Vacancies" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vacancies = blanks.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 BLANKS mean?
BLANKS noun- A small French coin, originally of silver, afterwards of copper, worth 5 deniers; also a silver coin of Henry V current in the parts of France then held by the English, worth about 8 pence .
- A nonplus .
- The white spot in the centre of a target; hence the object to which anything is directed or aimed, the range of such aim .
- A lot by which nothing is gained; a ticket in a lottery on which no prize is indicated .
- An empty space; a void, for example on a paper .
- (now chiefly U.S.) A document, paper, or form with spaces left blank to be filled up at the pleasure of the person to whom it is given (e.g. a blank charter, ballot, form, contract, etc.), or as the event may determine; a blank form .
- Blank verse .
- A piece of metal (such as a coin, screw, nuts), cut and shaped to the required size of the thing to be made, and ready for the finishing operations; (coining) the disc of metal before stamping .
- A vacant space, place, or period; a void .
- The 1 / 230400 of a grain .
- An empty space in one's memory; a forgotten item or memory .
- A dash written in place of an omitted letter or word
- The space character; the character resulting from pressing the space-bar on a keyboard.
- A domino without points on one or both of its divisions.
- Short for blank cartridge. .
- (in the expression ‘shooting blanks’) An ineffective effort which achieves nothing .
- To make void; to erase.
- To ignore (a person) deliberately.
- To prevent from scoring, for example in a sporting event.
- To become blank.
- To be temporarily unable to remember.