To add a bit to what Jerry has stated; Glycol based brake fluid is available in both regular and synthetic, with most of the synthetic being DOT 4. There is also a DOT 5.1 that is glycol based, it has a similar boiling point as the silicone based DOT 5.
Just from my own experience, stick with the glycol based fluid. Silicone based fluids can cause issues with incompatible rubber parts.
