Just to add to other posters
The more detailed your list of inventory is, the easier the process.
They can identify issues more quickly. For example, I had "medicine bag" listed only, they wanted to know WHAT prescription medication I was bringing back.
They also want to know WHEN and where you purchased items IF the items are less than 2 years old. Receipts need to be produced if they were purchased less than two years old and of significant value.
If you are going back to Vancouver, when your personal affects arrive in port, they ask you go to CBSA in downtown Vancouver (near the BC Hydro/ VCC buildings) with your list of inventory. When you get your stamp of approval then you can go and pick up the rest of your stuff.
It was an interesting process, paperwork heavy but painless if one follows all the steps.