Pattern rule dependencies order?

[Majeed, Zartaj]

When there is just % as a dependency in a pattern rule, it is processed
before other preceding dependencies in the rule. I am running make 3.79.1
and the behavior is identical on Solaris 8 and cygwin.

$ cat tester.mk
%/a: %/b %/c %
        @echo $@: $^

%/b:
        @echo target: $@
%/c:
        @echo target: $@
x:
        @echo target: $@
$ make x/a -f tester.mk
target: x
target: x/b
target: x/c
x/a: x/b x/c x

Why was dependency x processed before x/b and x/c?

Is % not allowed as a dependency? If it is, is this a bug or a feature?

Zartaj