The type of brake fluid you should use in your hydraulic brake depends on your brake model. You will usually find the type of fluid your brake was designed to use printed somewhere on the lever assembly or reservoir top cap. This makes it easy to identify and saves you from making the fatal mistake of introducing the wrong fluid and destroying your brake's internal seals.
While we're on the subject let's take a look at which way the various brake manufacturers lean when it comes to brake fluid choice. Take a look at the table below.
From that picture it's clear to see that DOT fluid is used by the vast majority of hydraulic brake manufacturers on the bike scene. But which brake fluid is best?