Not to be sneezed at.
Players who deliberately cough at other players or match officials can be red-carded, say football's rule-makers and the Football Association.
The International Football Association Board (Ifab) said such and offence fell within "using offence, insulting or abusive language and/or gestures".
It added: "As with all offences, the referee has to make a judgement about the true nature of the offence."
The guidance comes amid the global coronavirus pandemic.
"If it were clearly accidental, then the referee would not take action nor if the 'cough' took place with a large distance between the players," added Ifab.
"However, where it is close enough to be clearly offensive, then the referee can take action."
The FA also issued guidance for grassroots football which will come into force immediately.
In a document, it wrote: "If the incident was not severe enough to merit a sending-off, a caution could be issued for 'unsporting behaviour'."
It added that referees must not look to punish "routine" coughing and "action can only be supported where it is evident it was a clear act against someone else".
In terms of the Premier League and English Football League, there is no written guidance and it would be down to the referee's discretion as to the punishment.
Players who cough in the face of other players or match officials can be red-carded, say football's rule-makers and the Football Association.