The most common and most likely answer to this crossword clue is the 8 letter word PROTOCOL
I've seen this crossword clue in The Times
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More clues leading to the result PROTOCOL
- Expert not nerdy enough, ignoring repetitions of old rules?
- Poor colt somehow to produce good form
- Maybe original army officer's code of conduct?
- . Expert’s caught blocking apparatus of official procedure
- Crazy mount rearing following quiet procedure
- Body of rules confused poor clot
- Nonsense contained in fancy polo club’s code of etiquette
- 5 Spin doctor to officer: “It’s how you must behave”
- List of rules in old literature carried by professional officer
- It’s the custom for most of troops to reassemble in front of column
Buddy explains!

The straight part
We know that "code of conduct" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case code of conduct = protocol.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 PROTOCOL mean?
PROTOCOL noun- The minutes, or official record, of a negotiation or transaction; especially a document drawn up officially which forms the legal basis for subsequent agreements based on it.
- An official record of a diplomatic meeting or negotiation; later specifically, a draft document setting out agreements to be signed into force by a subsequent formal treaty.
- An amendment to an official treaty.
- The first leaf of a roll of papyrus, or the official mark typically found on such a page.
- The official formulas which appeared at the beginning or end of certain official documents such as charters, papal bulls etc.
- The original notes of observations made during an experiment; also, the precise method for carrying out or reproducing a given experiment.
- The official rules and guidelines for heads of state and other dignitaries, governing accepted behaviour in relations with other diplomatic representatives or over affairs of state.
- (by extension) An accepted code of conduct; acceptable behaviour in a given situation or group.
- A set of formal rules describing how to transmit or exchange data, especially across a network.
- The set of instructions allowing a licensed medical professional to start, modify, or stop a medical or patient care order.
- To make a protocol of.
- To make or write protocols, or first drafts; to issue protocols.