The most common and most likely answer to this crossword clue is the 6 letter word HEREOF
I've seen this crossword clue in Independent
H
E
R
E
O
F
Buddy explains!
The straight part
We know that "Concerning this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case concerning this = hereof.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HEREOF mean?
HEREOF adverb- Of this; concerning this.
- From or as a result of this.