Back to front, those standards (5)

I believe the answer is:

ethos

I'm a little stuck... Click here to teach me more about this clue!

'standards' is the definition.
(thesaurus)

'back to front those' is the wordplay.
'those' anagrams to 'ETHOS'.
But, I am not sure how this is indicated.

Can you help me to learn more?

(Other definitions for ethos that I've seen before include "Characteristic attitude" , "General disposition" , "Distinctive group spirit" , "Distinctive traits of a culture, time etc" , "Spirit (of a group, say)" .)

I've seen this clue in The Times and The Sunday Times.

Want a hint initially instead of a full solution? Install my app