Guidelines

Always write comments as you code, not afterwards.
Describe briefly the purpose of each procedure you write.
Describe changes you make to a procedure at a later date.
Indicate that you are using a function or construct in an unusual or non typical way.
Describe the purpose of variables in their names and do not use cryptic names.
Describe workarounds that you develop to overcome any known bugs.
Comments should be prefixed with just one apostrophe character followed by the comment in lowercase.
Only add comments that are useful.
Always put comments above the line of code.
Do not use any unnecessary formatting. A single apostrophe is all you need.
Add value added comments which explain why, do not add trivial comments.
Always check and amend the comments when code is copied and pasted.