Marcel,
Just some information that others could use, is all.
Seems like a good magazine Buck. 
I am not an advocate of installing deck ledgers with washers, I just wanted to point out that even though allowed by code, it might not be the proper way of installation.
And I like the way Nick explained it too!
I agree also, but our local AHJ’s are allowing wood spacers, if they are made of treated lumber. Guess, what, most are not. I inspect to INACHI recommendations, but the AHJ, rules against me, everytime. I don’t think there is ONE deck in the KC area, that will pass a INACHI inspection.
Don’t feel bad, none around here do also.
I built a small one last month and when I went to the lumber yards, (3) and home Deposit store, asked for a ledger flashing and they all looked at me like I was from another planet.
I just shook my head in disbelief. None to be had, and the only one hardware that had it available was to far. Go figure, so what is everybody doing when building decks.??:)
They are using WASHERS & SPACERS!!!