Valise, urn, box - applicable to all cases? (9)

I believe the answer is:

universal

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'applicable to all cases?' is the definition.
(I've seen this before)

'valise urn box' is the wordplay.
'valise urn' anagrams to 'UNIVERSAL'.
However, I am unsure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for universal that I've seen before include "Applying everywhere" , "Film producer" , "Everywhere applicable" , "Belonging to the whole world" , "Of worldwide scope" .)

I've seen this clue in The Irish Times.

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