It's vitally important that salient points are translated (9)
I believe the answer is:
essential
'it's vitally important' is the definition.
(I've seen this before)
'salient points are translated' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'salient' is 'sential' which is within the answer.
'points' could be 'es' (two compass points) and 'es' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'that' is the link.
Can you help me to learn more?
(Other definitions for essential that I've seen before include "must-have item" , "Crucial" , "Type of oil" , "'Absolutely necessary, required (9)'" , "Vitally important" .)