The most common and most likely answer to this crossword clue is the 3 letter word FAB
I've seen this crossword clue in Independent
F
A
B
More clues leading to the result FAB
Buddy explains!
The straight part
We know that "Remarkable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case remarkable = fab.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 FAB mean?
FAB adjective- Fabulous (great or spectacular).
- A manufacturing plant which fabricates items, particularly silicon chips.
- To fabricate, especially in the context of fabbers