Why does "manual%.html" match "manual.html" in some cases but not others?

[Jack Bates]

Why does "manual%.html" match "manual.html" in the case of
$(patsubst ../manual%.html,...) and ".PRECIOUS: manual%.html", but not
in the case of the target, "manual%.html: ..."?

I'm working on a Makefile for a project with source files,

manual.es.html
manual.fr.html
manual.html
manual.it.html
manual.nl.html
manual.pt.html

- http://github.com/jablko/manual

All these are compiled the same way, so I'm trying to write generic make
rules, http://github.com/jablko/manual/blob/master/css/Makefile

$(patsubst ../manual%.html,manual%.pdf,...) successfully substitutes
"manual.pdf" for "../manual.html" (as well as "manual.pt.pdf" for
"../manual.pt.html") and ".PRECIOUS: manual%.html" successfully matches
"manual.html" (as well as "manual.pt.html")

Unfortunately the "manual%.pdf" and "manual%.html" targets don't match
"manual.pdf" and "manual.html", respectively

Why does "manual%.html" match "manual.html" in some cases but not
others?