Hi Larry,
When Tom said "won't absorb moisture" in his post, I figured he was talking about silicone fluid. So yes...DOT-5 is silicone fluid. The partial sythetic stuff (ATe Super Blue?) is fine and it's still called DOT-4. The silicone stuff is best suited for military applications where the vehicles may sit for years at a time. You know, the secret hidden transports and tanks all over the world...stuff like that.
Regards,
Randy D.