Storage-class qualifiers like 'const' will work differently with typedef'ed pointers than with 'natural' ones. While this isn't typically a good thing with 'const', it can be very useful with compiler-specific storage classes like "xdata". A declaration like:
xdata WOKKA *foo;
will declare "foo" to be a pointer, stored in the default storage class, to a WOKKA in xdata. A declaration:
xdata WOKKA_PTR bar;
would declare "bar" to be a pointer, stored in xdata, to a WOKKA in whatever storage class was specified in WOKKA_PTR. If library routines are going to expect pointers to things with a particular storage class, it may be useful to define those storage classes within the pointer types.