Straightfroward letters of credit (6)
I believe the answer is:
direct
'straightfroward letters' is the definition.
I can't judge whether this defines the answer.
'of credit' is the wordplay.
'of' is an anagram indicator (the answer comes from or 'of' the letters).
'credit' with letters rearranged gives 'DIRECT'.
Can you help me to learn more?
(Other definitions for direct that I've seen before include "Order; straight" , "Aim; straight" , "the shortest way" , "Straightforward, frank" , "Immediate; organise (e.g. play)" .)