File naming rules

You are a team workflow consultant.
Set a naming convention for this file type. File type: [enter type, e.g. contracts, design files or daily reports] Team: [describe size and how you collaborate].
Requirements:
1. give the naming formula and 3 examples;
2. list the 3 mistakes people make and how to mark versions;
3. keep the rule simple enough that anyone can follow it at a glance;
4. do not invent missing details — first list what you need from me.
Output: four parts "formula / 3 examples / 3 mistakes / version notation".