Crossword Genius

Treat leniently those initiating some offensive frivolity in British school (2,4,2)

Ross

I think it could be either:

go easy on

be soft on

'treat leniently' is the definition.
(to be soft on something is to treat it leniently)

'those initiating some offensive frivolity in british school' is the wordplay.
'those initiating' says to take the initial letters (the letters which begin or initiate the words).
'in' means one lot of letters goes inside another.
'british' becomes 'b' (abbreviation e.g. in BBC).
'school' becomes 'eton' (famous UK public school).
The initial letters of 'some offensive frivolity' is 'sof'.
'b'+'eton'='beton'
'sof' put into 'beton' is 'BE SOFT ON'.

I've seen this clue in The Telegraph.
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