c. You must have express written permission to use another party’s trademarks or trade names, copyrighted or ....
What does that mean? You must have fast permission? It must be quick? Should we get that FedEx fast talking guy to say it? (If you are under 30, that reference goes deep into pop culture history - look it up).
It is "expressed written permission" as in actively given by the owning party.
To be fair, I did find this reference:
Express (adj) - clearly indicated; distinctly stated; definite; explicit; plain: He defied my express command.
But the whole idea of communication is to communicate. Something that may be correct on some obscure level does not add to the communication so say it the way the intended recipient can understand it.
Or, as some profess, limit your adjective use. You must have written permission to use......
Now, go conversate on that. (just joking about that "word" gives me the willies)