Many words in the English language can be reversed to form a new word. When a setter spots one, or wishes to reverse a piece of fodder that will make up part of the answer word, they will use a reversal indicator to show the solver that fodder needs to be reversed.
As with most indicators, the type of reversal indicator used will depend on whether the clue sits in an across or down position.
Here are some examples of both across and down clue reversal indicators:
To get STAB from BATS in an across clue the setter may write:
bats about ...
bats coming back ...
To get STAB from BATS in an down clue the setter may write:
bats rising ...
bats going upwards ...
Note that some reversal indicators, such as ABOUT, may be used in both across and down clues. As with other types of indicator only vertical or horizontal specific indicators should be used in down and across clues respectively.
Any word that fairly indicates a reversal may be used as a reversal indicator. Here are some more examples:
Across reversal indicators: IN REVIEW/FROM THE EAST
Down reversal indicators: GOING NORTH/KNOCKED UP
Here are some examples of reversal clues
Reversal with an abbreviation:
A detective set up woman (3)
a - a
detective - di (abbreviation of detective inspector)
set up - reversal indicator (for a down clue)
woman - definition
Reversal of a whole word:
Outlaw turned over for arrest (3)
outlaw - ban
turned over - reversal indicator
for - wordplay to definition link
arrest - definition