More doc cleanup

docs/urls.md

@@ -132,7 +132,6 @@ Possible URL parameters are:
 All forms where the user sets the parameters for the donation (amount and
 period) can be initialized using the following URL parameters:
 
-- `priv=1`: for the category, select “private” (default)
 - `period=m`: for the payment period, select “monthly with automatic renewal”
   (default)
 - `period=y`: for the payment period, select “yearly with automatic renewal”
@@ -140,9 +139,6 @@ period) can be initialized using the following URL parameters:
 - `period=o`: for the payment period, select “one-time payment”
 - `amount=<number>`: initialize the amount
 
-If an amount is given, but priv/corp and/or period are missing, the form tries
-to guess the most reasonable variant.
-
 Examples:
 
 - `https://my.fsfe.org/donate?period=o` initializes the form with our