Some proof-reading of the PEP.  I apologise if this is out of date.

1) In the beginning of the "Mapping Pattern" section:
             "{" (pattern ":" pattern)+ "}" 
    This is spelt inconsistently: there is a `+` before the closing `}` but not after the opening `{`.

2) The second code snippet in the "Guards" section:
	values = [0]

	match value:
	    case [x] if x:
	        ...  # This is not executed
	    case _:
	        ...
	print(x)  # This will print "0"

   Inconsistent spelling: `values` and `value`

3) At the end of the "Named sub-patterns" section:
	"PEP 572"
   It would be more helpful to say "PEP 572 (Assignment Expressions)"

Rob Cliffe