There is a section in Docs > Accounts > Billling > Purchase Invoice mentioning the Update Stock (Purchase Invoice)
I suggest to add here explanation to check this Update Stock checkbox when making Purchase Invoice that doesn’t have a Purchase Receipt.
Otherwise an entry in Stock Received But Not Billed will automatically be created, and this will require an adjustment journal entry later to update the stock and nett-off the Stock Received But Not Billed account.
I see many of my users are confused by the existence of the Stock Received But Not Billed in the Balance Sheet. And the values are negative.