Dear member,
For the misconduct of a minor nature by the employee, the administration may issue the "warning letter". However, the warning letters need customisation, and one has to write clearly, what was the event, what the failure of the employee etc. Therefore, there cannot be a "standard" warning letter that can be used for all types of misconduct.
Go through this forum, check the drafts of the warning letters and prepare a draft of the warning letter on your own. Some senior like me will correct it.
Thanks,
Dinesh Divekar